[Photographs: J. Kenji Lopez-Alt]

Traif, a small, classy bar and small plates restaurant that straddles the border between the hipster and Hasidim in Williamsburg, is billed as a concept restaurant, though the concept is far from kosher. The exact opposite, in fact. Chef/owner (and Jew) Jason Marcus and girlfriend Heather Heuser have named their restaurant in a style that should appeal to the neighborhood's sensibilities: Traif is the Yiddish word for non-Kosher foods.

Fittingly, the menu consists largely of pork, cheese-covered meats, and shellfish.

Often, when concept is put before flavor, menu design can suffer, with ingredients being crowbarred into dishes just to fit a theme. Luckily, Chef Marcus doesn't make this mistake and is not afraid to serve some dishes that are perfectly kashrut.

The space is cozy but hip, and the kitchen is tiny. A single range and salad station is crammed in behind the bar, manned on a busy Friday night by Marcus and a single assistant. It's remarkable that the two-man team is able to turn out dishes so fast out of such a tight space, particularly with a menu over twenty plates long. Mostly small, though a few cross into light entrée-sized offerings, the plates are ideally shared between three or four people.

The range is eclectic. A smattering of Asian-inflected dishes, like the tender and succulent five-spice glazed chicken wings, are wedged next to American classics like barbecued beef sliders with sweet potato fries.

Those fries, for the record, are the best sweet potato fries I've ever had. Well seasoned and perfectly crisp (as crisp as any real potato fries I've had), with a sweet, creamy center. They come served with an incredibly addictive smoky, spicy mayonnaise. (It's a good thing I liked the mayo, because variants of it are featured in no less than four separate dishes).

Despite the range, Marcus is at his best with simple, ingredient-driven dishes: The best dish on the menu is a simple affair of tender, perfectly sauteed, bright green broccoli rabe topped with an inch-thick slice of toast soaked in a savory portabella and truffle gravy. The crisp-edged sunny-side up egg is heavily peppered and delicious. Truffle oil also makes a less impressive appearance in the dressing for a fig salad, where it dominates the other flavors in the bowl.

Like the unfocused menu, the Asian-inflected dishes are where Marcus' food really gets confusing and often derailed. Duck confit lettuce wraps sound appealing but are far too sweet, and even sweeter when wrapped up with the banana-tamarind chutney provided. It begs for some herbal freshness, heat, and acid to bring it into focus.

Equally muddled is the tuna tartare, where the powerful flavors of spicy mayonnaise (not dissimilar to the one that works so well on the sweet potato fries) and Indonesian kecap manis preclude any chance of actually tasting the bigeye tuna. Served on top of a greasily fried slice of eggplant, it's a clumsy dish.

Other fried dishes are similarly disappointing. Delicate squash blossoms are stuffed with excellent mozzarella from Brooklyn-based Lioni, but the dish does justice to neither the squash, nor the cheese, coming off as a not much more than an expensive mozzarella stick.

Of the truly traif dishes, he's best with shellfish. Scallops are nicely browned with a rare center (though the creamed corn they come with is mediocre). Juicy and briny spot prawns are cooked in the best possible way: Blistered shell-on with a barely cooked, tender center. For best results, suck on the head after eating the tail. The familiar spicy mayonnaise makes another appearance on the plate, but this time it's perfectly suited to the similarly smoky prawns.

Rock shrimp are also excellent, a tart tomatillo salsa enhancing their brininess (skip the greasy corn cakes they come served with).

Pork products, on the other hand, are not treated with as much reverence. Braised pork belly is described as crispy on the menu, but arrives at the table soft and anemic looking, even if it still tastes good (it's hard for pork belly not to taste good). similarly, the bacon-wrapped blue-cheese-stuffed dates are well balanced and tasty, but the bacon is soft.

With such an up-and-down experience, it was tough to know what to expect for dessert. Fortunately, it was another upswing. Bacon doughnuts (their signature dish, perhaps) were excellent: Light, fluffy and eggy, with a crisp, dulce de leche-glazed exterior. I'm personally tired of the whole bacon-on-everything meme, but in this case it fits nicely: like putting the bacon, waffles, and maple syrup in your mouth at the same time. Coffee ice cream rounded out the trite but delicious dish.

Even better was the key lime pie, delivered daily by Mr. Marcus' mother. Light and creamy with an assertive citrus tang, it was about as good as key lime pie gets.

The meal unfortunately ended on a downer: The cheese plate consisted of three cheeses served fridge-cold on a hot plate. One, an Irish Cheddar, still bore the impression of the shrink-wrap packaging it came in. It was happily removed from the check.

Despite flaws in the food, Traif remains a great, inviting, and fun space to drink in, and the cocktails are mostly excellent. My wife's got a thing for bacon-flavored booze, and was enamored of the Rude Little Pig, a tequila-based concoction that comes rimmed with Pop-Rocks sized flecks of crispy bacon bits. I preferred the Moroccan Whiskey, essentially a Whiskey Smash toned down with iced tea.

Like their lush back garden, their wine list is small but well curated.

Does Traif bear an out-of-the-way visit? Definitely not. The fare is no better than many other similar neighborhood gastro-bars, but a neighborhood bar is, after all, what it is: casual, inexpensive, and fun. And at that, it excels.