Rinse fish and seafood with cold water and pat dry.
Heat oil in a large saucepan. It is the right temperature when small bubbles rise against a wooden spoon handle.
Season fish and seafood with salt and pepper and coat with flour, tap off excess flour.
Fry in portions in hot oil until golden brown, larger fish 5-6 minutes, smaller fish 4-5 minutes and seafood for 2-3 minutes. Drain on paper towels and keep warm in the oven until ready to serve.
Serve warm with lemon wedges.