Heat oil in a skillet and add onion, garlic and ginger. Cook until tender but not browned. Add ají (chilli), lemon juice and white wine. Cook 4 minutes to evaporate alcohol. Season with salt and pepper. Add tomatoes and place fish fillets on top. Lower heat and cover skillet. Cook over low heat until fish is tender. Time for cooking fish varies with type and thickness of fish fillet.
Serve with cooked white rice and sliced boiled potatoes
How to fillet, skin and debone fish