Dishes with the term "Florentine" (in the style of Florence) usually contain spinach.
Serves 2
Build a fire in a hooded outdoor grill (or pre-heat the oven to 350). Place each trout (open with the flesh facing upward) in the middle of a piece of aluminum foil at least 2 1/2 times the size of the fish. Place a thin layer of spinach on the trout. Sprinkle on the onions. Drizzle on the butter and wine. Season. Seal the package. Place over hot coals and close the hood (or place on a baking sheet in the oven). Cook for 12 minutes. Serve warm.