When New York winters send local fish to warmer waters, Alex and Stephanie Villani, whose Blue Moon Fish stand at the Union Square Greenmarket is the best source of seafood anywhere in the city, follow suit, taking leave of Long Island each January and February for an annual break in the Florida Keys. I’m down here on vacation myself this week, and wasn’t sure they’d even remember me, but the first thing Alex said after “Hello?” was “Wanna come for dinner tonight?” We rolled up at sunset and he welcomed us with rum cocktails in hand but the main gustatory event, over hours of Greenmarket chatter — I used to work there, too — was an enormous pile of stone crab claws, plucked that afternoon from his nearby traps. After a simple steaming, Alex smashed each one with what looked like a stone billy club and which must have once been half of a giant’s mortar and pestle. They were meaty and succulent, spectacular with Stephanie’s quick dip of mayo, mustard and—of course—fresh key lime juice.
