Single mindedness rules on the corner of 45th Street and Ninth Avenue. Out of what used to be the over-draperied rococo mess that was Jezebel have emerged two discrete restaurants that both take their names from a single dish. The Jezebel business has been scaled down to about a tenth of its former size and has re-emerged as Piece of Chicken, a table-free kitchenfront that sells $1 portions of ribs, greens and fried chicken. Some might view the move as a decline into reduced circumstances, but the focus has done Jezebel’s kitchen a world of good–the food is consistently wonderful, and now that it has no seating (nor piano player, nor porch swing), its overhead is laughably low. All of this adds up to a profitable business that adds real value to the neighborhood.

The teensy kitchen’s new neighbor–actually the occupant of its former space–is a familiar one. Five Napkin Burger is another collaborative effort from Andy D’Amico and Simon Oren, the Nice Matin duo that brought first Marseille and then Nizza to the very same block of Ninth Avenue. If this were Monopoly, the pair would be buying hotels right now.

Five Napkin Burger differs from its siblings in its rejection of a regional theme of any sort–the menu features the eponymous ten ounce chuck burger alongside sushi, pork chili, and Tunisian salmon tabbouleh. You could broadly call the food Amerasian Fusion Plus, but above all else, the restaurant’s repertoire always comes second to its mammoth burger (pictured top, $13.75). This hierarchy is just about right: The signature dish is Five Napkin Burger’s best, and despite its copious goopiness (pictured below right) it is worth a visit on its own. We are especially fond of the caramelized onions and aromatic rosemary aioli, even though they lubricate the bun so much that it is hard to even keep the sandwich intact enough to take a first bite. On our initial visit, we spotted a neighboring table anchoring slippery bun to patty with toothpicks, which is a tactic that works, but simply cutting the burger into quarters achieves the same results without the danger of puncturing a cheek.

Indeed, burgers make up the best items on the menu: the Italian turkey burger ($10.95), prepared with tomato sauce and peppers, reminds us of a very decent meatball sub, and the Ahi tuna burger (pictured left, $13.95) benefits from the contrast between the sweetness of the soft, brioche roll and the savory soy and wasabi mayonnaise. As much as we enjoy Five Napkin’s medium rare tuna burger, the tempura onion ring really ought to be served as a side–it adds nothing to the sandwich apart from more calories.

Most other dishes on the menu are adequate but not very special, especially the bland smoked tomato grits with shrimp (brunch only, $14.25) and the greasy, heavy pork chili (brunch or starter, $12.75). Similarly, the sushi, a puzzling companion to a hamburger-focused menu, is only satisfactory and probably ought to be ditched in favor of more light salads. We would also love to visit once when the waitstaff did not try to upsell us so wantonly at every stage of our meal.

But really, the timing could not be more perfect for Five Napkin Burger. Hell’s Kitchen has needed a casual, pretty reliable American bistro for quite some months–a gaping market void that can be traced neatly back to the day when Film Center Café got its extreme chrome makeover and suddenly decided it was Cookshop North. Sure, Five Napkin Burger could be 20% better than it is right now with very little effort, but with all signs pointing in the right direction in its early days, D’Amico’s kitchen should have plenty of time to revise and edit–as long as they leave their delightfully messy burger alone.

Five Napkin Burger, 630 Ninth Avenue (at 45th Street), 212-757-2277.