"Pacifica Del Mar, seafood is our passion! How can I help you?" are the first words you hear when you phone this restaurant. And phone you must. This place is a-hoppin' -- especially now that the San Diego County Fair has opened and racing season is racing up. Reservations are a must.

The restaurant's dinner menu is seafood-swathed indeed, with 9 of a dozen entrées, and all but 1 of 11 starters, rising from the sea. Lunches are more eclectic, with sandwiches, burgers, salads, and seafood pastas. For a more casual lunch or a creative breakfast, the adjunct Pacifica Breeze Café, one floor below on the mezzanine of the mall, serves similar fare (e.g., grilled salmon sandwich, seafood pasta) at modest prices on an outdoor patio. (Evenings, it's available for catered parties.) The main kitchen provides all the Café's recipes and most of the hot entrées, while the Café's kitchen makes casual cold dishes -- sandwiches, wraps, etc. -- on-premises. (One lunchtime, when I wasn't even hungry, I fell in love with their overstuffed "BLTA" burrito wrapped in a spinach tortilla, served with hot, house-made yam chips.)

The upstairs restaurant attracts locals and tourists alike -- sometimes becoming victim to its own popularity. Crowds keep a restaurant alive and prospering, which means the chef can purchase prime ingredients. But cooking can slip when the slamming kitchen is stretched past capacity, attempting to feed three or four hundred diners, not to mention whatever's happening in the private banquet room.

This is a tale of two dinners. When first I arrived at prime time with the stalwarts of the crew (Sam, Lynne, and my partner), the joint was jumping. For mysterious reasons, the entire mall was packed, with cars lined up, waiting to get into the garages -- a human grunion run. Our reservation bought us a seat in Dining Room #1, separated by an aquarium from the howling bar. Immediately, we envied the patrons who'd snagged Room #2, between #1 and the outdoor patio, which was a little quieter and had softer lighting. It was a Thursday, "half-price wine night," but that wasn't the issue. "Most of these people don't even know about 'wine night,' " said our waitress. "The crowds are totally unpredictable. Some weeknights, we have a small kitchen staff and a full house. Other nights, we have a full staff and a half-full house. You just never know when or why."

We started with a terrific bottle of citrusy New Zealander Kathy Linskey Chardonnay, and a round of Puget Sound oysters on the half shell -- fresh and juicy, served with a mild vinaigrette based on mirin (Japanese sweet cooking wine) and a wasabi cocktail sauce, which happily proved less fierce than it sounded.

Tender house-smoked salmon slices were dressed with olive oil and Moroccan-style preserved lemon and came with a quartet of crisp, hollow "beignets" -- closer to deep-fried biscuits or cream puffs than New Orleans' famous donuts -- filled with melted cream cheese, inviting you to assemble a gourmet version of bagels and lox. I loved the combination, but Sam and Lynne found the salmon greasy. Just goes to show, one woman's meat is another's poisson.

Our sentiments toward the Dungeness crabcakes ran in the opposite direction. The two crunchy-seared cakes, with minimal filler, were smeared with a pungent green wasabi rémoulade and garnished with puddles of apple-fennel purée. My friends loved the dish, while I felt that the rémoulade overwhelmed the crab's natural sweetness.

You get a soup or salad when you order an entrée, and we were all happy with both. A hearty Yukon Gold potato-leek bisque gained smokiness and character from bacon cracklings and spring garlic greens. We left not one drop behind. The house salad of organic mixed greens with dried cranberries, caramelized walnuts, and blue cheese is a crowd-pleaser in its cider-mustard vinaigrette. Meanwhile, we enjoyed a lightly herbed sourdough bread with bits of dried black currant, a product of nearby O'Brien's Bakery.

By then, every table was full and the din was growing painful. The architecture and sheer size of the restaurant amplify sound, but so does the Very Del Mar crowd: On one side were five Masters of the Universe -- well-dressed businessmen with booming, confident voices. On the other side was a "girls' night out" sextet of pretty young things in low-cut dresses, periodically emitting choruses of yips and squeals. "Is there a pack of Chihuahuas in the house?" asked the Lynnester.

The kitchen, too, was having a hard time with the ravening crowd. In a signature entrée called "Pacifica's Barbecued Sugar-Spiced Salmon," the fillet was overcooked, so dry and salmony-tasting that it overpowered its sweet mustard sauce. But the accompanying mound of garlic-mashed potatoes was sublime, closer to a gratin than a mash with its crunchy exterior and creamy center. The spuds were topped with firm Chinese long beans. I'd gladly order this dish again on a quieter evening, when the grill chef doesn't have to play the whirling dervish. Meanwhile, alas, a plate of herb-crusted Great Lakes whitefish seemed to have left its flavor back in Michigan; all we could taste was herbage. It came with doughy spinach gnocchi and a beurre blanc mixed with strips of Asian wild mushrooms (whose precise species neither we nor our waitress could identify).

Chef Idso always includes an entrée of pristine Atlantic scallops on the menu, recipes changed according to seasonal inspiration. Some of these are better than others. The important thing is that he takes chances and focuses on local produce. This time the result was debatable: the precious bivalves were plated atop Chino Farms fresh peas of variable quality -- some young and sweet, others old and mealy. (The weather this spring was awful for growing peas; I had a similarly distressing backyard harvest.) Also involved is a green-olive butter sauce dotted with chewy wheatberries and edamame, a combination hedging awfully close to health food. To my tastes, if you crave scallops, the clean-flavored appetizer "Seared Scallops on the Half-Shell" (with cucumber, pea sprouts, and a spicy yuzu vinaigrette) is a better bet.

Oddly, at this fish house, our token meat dish was a smash. Pacifica cures a boneless rib-eye by rubbing it with salt, garlic, bay, oregano, and rosemary. It's rolled, wrapped, and tied with the herbed side in, then set in the fridge for three or more days while the flavors permeate. Before cooking, they scrape off the herbs. What emerges from the grill is a mouth-blast of meatiness, a Choice-grade steak that tastes and chews like aged Prime. It came rare, as ordered, dripping with its own salty au jus, with Stilton cheese spread on top like butter, blasting the flavors into orbit. Alongside are frizzled onions, fingerling potatoes, and Chino Farms summer squash. I firmly claimed the doggie bag, declaring, "I need to strip everything off that puppy and look at it naked!" Tasted side by side with some leftover so-called Prime steak from another eatery, it won by a dozen lengths.

When we couldn't decide on a dessert, our waitress suggested, "Why not get 'em all?" A sampler plate ($14) offered most of the evening's sweets. (All but the Gelato Vero ice creams are house-made.) An upside-down pineapple cake resembled breakfast coffee cake. A flourless chocolate hazelnut cake was dark, fine-grained, and not too sweet. Ice cream bonbons had dark chocolate shells studded with almonds, filled with vanilla-bean gelato surrounding a sphere of marzipan -- very trippy. Also appearing were apple-croissant bread pudding, a refreshing sorbet, and the mandatory crème brûlée, a creamy version with enough sugar and vanilla to taste like Swiss Miss pudding.

A few weeks later, my partner and I returned on an earlier weeknight at a quarter to six. Not only was our food more consistent, but we snagged the best possible table, at the front edge of the heated outdoor patio, where we enjoyed a panorama of the street and the sea through a thick sheet of glass that blocks all street noise.

This time we noticed a group of mini-starters listed on the right side of the appetizer menu: a half-dozen sampler-size portions for $3 apiece, amuse-bouches at a couple of bites each. A "lemongrass poached prawn" was served as a stack: On top, a transparent cuke slice, then a prawn, then sliced avocado and another prawn in a puddle of cocktail sauce. It resembled a miniature Mexican shrimp cocktail -- with a cooking-school degree.

A full-size starter of Baked Oysters is an improved version of Oysters Rockefeller, with the bivalves tucked between a layer of lightly cooked spinach and a brandied cream sauce strewn with wisps of mild, melted Parmesan. The sauce isn't heavy and it's fully cooked before assembly, so the oysters emerge barely warmed, with all their succulence intact, robed but not drowned. Even the Parmesan is just right: Sometimes a mild Wisconsin cheese like this can work better than an imported powerhouse.

A "Japanese clam chowder," scallion circles afloat on top, combines miso, water chestnuts, shiitake strips, and the merest trace of minced clams. Apparently more shiitakes were puréed with the miso, since the thick, pale-brown broth tasted like an Asian twist on cream of mushroom soup. My partner, enamored of Japanese cuisine since his teens, kinda-sorta liked it but warned me (accurately) that I wouldn't. Remembering the delicate clam miso at Samurai Restaurant, I found this version one of those stabs at fusion cuisine that leaves scabs and scars on that poor, abused cooking genre. The soup is one of the restaurant's most popular dishes, however, so judge for yourself.

Mustard catfish is a Pacifica signature dish that appears at several other San Diego-area restaurants, including Cafe Pacifica in Old Town, and Fifth and Hawthorn in Midtown, to name just two. No accident -- all these eateries (and several more) originally sprang like dandelions from Cafe Pacifica. Pacifica Del Mar's rendition is especially sophisticated. You get a thick hunk of mild fish coated with a mustard-spiked breading touched with cayenne. The surface is squiggled with a foamy, slightly spicy green-onion aioli. (The foaminess? They shake it up before spooning it on.) A moat of potato-corn succotash surrounds the fish, with sautéed mini-diced Yukon Golds subbing for lima beans, a great idea, since hardly anybody really likes limas.

Sautéed Northern halibut is another Japanese-based fusion dish. Thick, evenly cut rectangles of fish are cooked to a perfect translucence, topped with "onion-miso marmalade" with a kick of lime juice. After this promising start, they're set afloat in a pool of sweetened-miso broth with udon noodles, chopped asparagus tips, and squeaky beige shimeji mushrooms (which resemble enoki in their absence of flavor). Diners whose favorite fish is mild halibut will probably love this symphony in the key of understatement.

That evening's dessert sampler was whittled down to a trio. The flourless chocolate cake was even better this time, topped with espresso gelato sprinkled with candied shreds of orange zest. The crème brûlée was the same. The bon-bons suffered from stale almonds, including those in the marzipan.

I can't say that I adore every single dish on the menu at Pacifica Del Mar. But given generally excellent ingredients (local produce and top-flight seafood) and a creative chef who's willing to take some risks, I don't have to love everything -- I do have to respect it.

ABOUT THE CHEF

"I decided to become a chef during my second year of college," says executive chef Chris Idso. "I started studying a business curriculum. I'd been working in restaurants since my junior year in high school, and I decided that cooking was really where I wanted to be. I liked the creativity, the flexibility of time, and I pursued that and got involved in an externship. I started working in hotels and resorts in Arizona, where I'm from, for about 5 years, then I worked in Lake Tahoe for a couple of years. About 15 years ago, I got serious and moved to the Bay Area to go to culinary school [at California Culinary Academy in San Francisco]. I started working in free-standing restaurants and really liked that -- lots of creativity, no rules. The Bay Area was the mecca for food and restaurants at the time."

Idso worked at deluxe suburban restaurant La Tourelle and then became executive chef of the highly reputed Lascaux. "Lascaux was my first real chef job, and then that restaurant was absorbed by the Kimpton [Hotel] Group, which transferred me to Splendido as executive sous-chef. Then one of the Kimpton vice presidents went into business with the family that owned the Franciscan on Fisherman's Wharf, which was in the process of renovation. I worked there for about five years. We tried really hard to upgrade the whole waterfront dining scene, and we were successful to a degree, but it was very difficult. The tourists still wanted the tourist food. At that point, I started researching other options, especially in the San Diego area.

"Pacifica serves the same tourism market, but a lot higher end than at the Wharf, and we also have a high-end local market. I really fell in love with Kip [owner Kip Downing], fell in love with the restaurant and the area, and have been here for a little over five years. The San Diego diner is not quite as adventurous as the Bay Area diner -- but it's certainly a happy medium from what I did at Fisherman's Wharf. There's much more creativity on the menu...What Kip specifically wanted was more a blend of Bay Area-type dining -- more product-driven, more local stuff... It's taken a while to find them but there are organic farmers, cheese-makers, mushroom-growers here. What I really found fun was to identify them and put them in play. Now, every one of my purveyors is local -- Chino Farms, Valdivia Farms, Specialty Produce gets me some local organics, Leong-Kuba for most of my seafood.

"Some of the challenges here are operating from eight in the morning until nine or ten at night. We have 25 guys in the kitchen, and we've added another 50-seat dining room and have increased our catering to about a million dollars a year. I have to fall back on my hotel restaurant experience to handle this -- we do everything but room service. Evenings, we're pretty full from about 7:00 to 8:30, later on weekends, and we try to make every plate perfect. It's true that the kitchen can get stressed when we have 300 covers.... Last winter we also developed our 'to-go menu' program. It's good for our local trade, which rounds out our business through the winters, keeping us going in the off-season. We really listen to the locals, especially in the Café, and we shape the menu to what they want."