We have no official opinion about the great foie gras wars of 2006. We promise to think about it. For now, we'll take a fatty slice of heaven where we can get it, and when it's served as cunningly as at Salt, where it's clearly first rate, placed atop a miniature well-seasoned hamburger, and accompanied by truffle oil and a red-onion marmalade--and we'll take it again and again. Or at least until, at $15 a pop, our fundage dries up. (Which it has). The "slider" burger goes very nicely with Salt's duck-rendered french fries, served Belgian-style in a paper cone. The thing we like best about the "slider" burger is the statement it makes about chef Jason Ambrose's culinary thinking: He's out to have some fun.