Piatti shouldn't be good at all. It's in a mall (University Village). It's a "concept restaurant" (hearty Italian). It's part of a chain (15 outlets, most in California). That Piatti is not just good but darn good requires some explanation. A look at the map on the corporate Web site offers one good clue: Most Piatti restaurants in California are in more or less moneyed communities like La Jolla, Carmel, and Mill Valley, where the word "mall" does not imply mediocrity, or in wine-country centers like Sonoma and Yountville, where people tend to take their food seriously. Another, stronger clue appears only after you're already seated in the big, welcoming U Village Piatti: the name "Felix Acosta" at the bottom of the menu. Acosta has been earning accolades from Northwest diners for years, making the rounds from Dahlia Lounge, the Painted Table, Marco's Supperclub, and the Yarrow Bay Grill before being recruited to head the kitchen at the Seattle Piatti. Acosta's cred was clearly a significant factor in his hiring in September 2002, because, like that at many chain restaurants, Piatti's menu is pretty much centrally set, with a dozen or so of the main offerings determined seasonally by Piatti World Headquarters in Yountville. But the apparent uniformity is belied by each restaurant's tacit permission to prepare the specified Caesar salad or rigatoni in bolognese sauce in its own way. With Acosta in the kitchen, the corporation's trust is well placed. Carpaccio is a trendy dish that rarely rates the attention invested in it; Piatti's ($8.95) is perfect, the buttery smooth, almost transparent slices of tenderloin enlivened by their lemony dressing, sprigs of arugula, and curls of Parmesan. The ample appetizer platter of fried calamari ($8.95), another command performance, is succulent to the last crispy nugget, the flavor not overwhelmed by the accompanying garlic mayonnaise. An order of clam linguine ($14.95) eschews the Italian sausage and tomato flavoring specified in the central menu, presenting rather a classic clear wine-and-garlic sauce that demands to be mopped up to the last drop with the restaurant's house-baked focaccia. And other dishes spring entirely from the tastes and aspirations of chef Acosta and his staff: the gnocchi in two sauces, pesto cream and marinara with toasted pine nuts ("I don't want to toot my sous-chef's horn," Acosta says, "but these gnocchi are light"); the simple pizza margherita on dough made daily; the two-deck lasagna (one layer stuffed with ricotta, the other with stewed mushrooms, eggplant, and tomato). And then there are the house-made desserts. But if you're like us, you'll be replete too soon to appreciate them fully (although that strawberry panna cotta looks awfully attractive . . . ). Piatti may just mean "plates" in Italian, but at this Piatti, it's what's on the plates that counts. firstname.lastname@example.org Piatti, 206-524-9088, UNIVERSITY VILLAGE, $$. 11:30 a.m.–10 p.m. Sun.–Thurs.; 11:30 a.m.–10:30 p.m. Fri.–Sat.