Zak Stern's deli is what might have happened had Eastern European Jews first arrived in South Florida rather than the concrete jungles of New York City. Chef Melissa Sosa, age 25, has a notebook full of recipes but an empty ingredient checklist. After all, there is no pike, cod, or similar white-fleshed fish that is required for so much of Jewish cuisine in the waters off Miami. But with a little digging, some glimmers of hope have appeared. Sosa uses the little-known species blue runner from purveyor Trigger Seafood to make a fish salad that is just as smoky and salty as anything one might pull from the North Atlantic. And the sandwich ($13) it yields is nothing short of miraculous. Dill fronds and flecks of celery help accentuate the fish and provide crunch alongside a verdant fan of butter lettuce. The kitchen is also toying with Florida grass carp, a native species found in the state's bountiful wetlands that might work to make gefilte fish. For the unadventuresome, the corned beef sandwich ($16), which brings thick slices of cured brisket piled onto slices of horseradish-mustard-slicked corn rye, will never be a bad choice.