The line between inventiveness and gimmickry can be a fine one. When a new restaurant specializing in ceviche opened in Midtown East, I thought it would be a palace of the latter — a thin, uninteresting collection of citrus-cured seafoods with various Latin American frills.

But Todd Mitgang’s ceviche bar, Crave, is deeper and less earthbound than I feared. Taking the ceviche technique as a starting point, the chef and co-owner, who polished his raw-fish skills at Kittichai, whips up a wide variety of snacks. Everything from veal to foie gras gets the treatment, soaked in solutions made with yuzu, Champagne, yogurt, and any number of other ingredients. To broaden the possibilities, Mr. Mitgang works within a loose definition of ceviche. Traditionally, it’s a preparation wherein the acid from a tart marinade, usually citrus-based, “cooks” a protein, performing roughly the same job that heat does, but without heat. At Crave, “to ceviche” means roughly “to marinate,” whether or not the fish (or whatever) has been chemically cooked and turned opaque by the process.

Thus, the thick-sliced arctic char ($14 for a small portion, $17.50 for a large) retains the translucent color of raw fish — which it is, despite a luxurious bath in Champagne and a salty truffle scent, and appropriate garnishment with caviar and fresh strawberries. The result is a richly flavored, refreshing plate, without a hint of traditional ceviche’s Latin American origin.

The menu’s influences come from all over. Kampachi, a farmed relative of yellowtail, is tossed with firm chickpeas in a mild curry sauce, with a topping of yogurt and cucumber providing South Asian realism ($13.50/$16). The fish’s surface is lightly seared, but again, it’s essentially more raw than what I’d call ceviche. And the same goes for wild king salmon ($15/$19) that’s soaked in excellent sherry vinegar with a paste of chopped capers. For a change, there’s something warm on this plate: sautéed curls of chorizo and oyster mushrooms, which give a garlicky fullness to the dish. Balls of tuna tartare ($12), served atop rounds of yuca root, are saved from ordinariness by a Japanese sprinkle of seaweed and sesame.

When Crave does serve a classic dish, the customer isn’t allowed to forget it. The shrimp ceviche ($9/$13) is referred to as “traditional” on the menu and incessantly by the staff as well; and indeed it has authentic touches, such as seared kernels of fresh corn mixed into the limey broth, as well as spiced popcorn strewn on top. Roomy restaurants, such as Gotham Bar and Grill, that take the word “bar” in vain, have stretched the word out of shape, but Crave Ceviche Bar restores meaning to it: It’s a literal bar, a sliver of a place. There are a couple of small tables but most of the clientele squeezes and jostles onto stools at the tall stone bar. Every night of the week, the waiting list on the chalkboard up front is several couples long.

The ceviche concept is overextended once in a while, as with miniature burgers ($6.50 apiece) of ground filet mignon, “ceviched” in Worcestershire sauce and served, without warning, ice cold. It’s not what you want from ceviche and definitely not what you want from a hamburger. A special of foie gras ($16) works surprisingly well, though, the lobe of luscious liver marinated overnight in yuzu, then seared. The citrus adds a lovely depth of flavor, and integrates more effectively than the classic way of serving foie gras in a pool of tart-sweet sauce.

Mr. Mitgang makes a respectable version of pupusas, the thick Salvadoran stuffed tortillas: as a side dish, fried crisp and topped with savory chorizo ($8), or as a summery, multicultural main course in which the traditional heaped topping of Salvadoran coleslaw is interspersed with hunks of snapper doused in Thai fish sauce and tart calamansi juice ($16.50). And hot, crisp-fried kimchi tops an otherwise cool Korean-tinged dish of calamansi-marinated pale squid ringlets, dressed with ginger and tossed with juicy shiitake mushrooms.

Sangria is the drink of choice at the bar, served in substantial ruddy glasses ($9) or pitchers ($32) to which apples and pears give an autumnal flair. It is a far cry from the usual citrus-piqued sangria and a nice break from the citrus-heavy rest of the menu. There’s also bottled beer ($5), which can be optionally doctored with lime and plenty of hot sauce, for a $1 surcharge. Thirty wines, many offered by the glass and most from Spain and South America, include a delicious Chilean carmenere blend from Vina Montes ($11 a glass/$42 a bottle) and a potent xarel-lo blend from Spain’s Segura Viudas. Impressionistic epithets such as “charred cherries” and “blue raspberries” provide a sort of guidance through the list.

Dessert doesn’t get the ceviche treatment, mercifully: There’s only one choice, a complimentary bowl of chili-fired caramel, chocolate, and cream, so dense it’s hard to lick from the little spoon.

Crave (946 Second Ave., between 50th and 51st streets, 212-355-6565).