Quite off the beaten path in Key West is Mo's restaurant at 1116 White Street. The former owners were French Canadian who taught the current owners, Haitian-Americans, all their recipies. Now the menu reflects French cooking across all the latitudes.
Recommended: French onion soup, garlic bread, seafood casserole du jour, oxtail and goat specials. The beans on the side are wonderful. Ask for the little thimble-full of their hot pepper sauce, it's potent but tasty.
The place is small, the kitchen is open, and a TV is sometimes blaring Haitian news.
For dessert, they offer a wonderful apple tart/cobbler. Or, head a couple doors down to Mathiessen's Fourth of July for homemade ice cream.