God forbid the Underground Gourmet should ever find himself in a holding cell on death row, with little hope of Ms. U.G. coming through with the file baked into a cake or the governor issuing a stay of execution. But if he does, at least he’ll know what to order for his last meal on Earth. That would be the foie-gras-and-smoked-Cheddar grilled cheese sandwich from Chez Sardine, the latest addition to Gabriel Stulman’s burgeoning West Village empire. This is one of those dishes that fall squarely under the heading of things that sound horribly wrong but taste incredibly right. Yes, it’s fat on fat and — taking into account the generously buttered bread — even more fat, but the beauty of this stupendous morsel lies in its unexpected balance. The Sullivan St Bakery filone is expertly griddled to the golden-brown point where slightly greasy meets delicately crisp; the house-smoked fromage is as well melted as a jar of microwaved Velveeta; and the kitchen deploys the foie gras almost like a condiment in little half-moon dabs so it doesn’t steal the show. Pickled onion and cucumber deliver some acid and crunch, while the accompanying bottle of green Tabasco is a nice touch that proves this is one glorified grilled cheese that doesn’t take itself too seriously.