- take a large mixing bowl and combine all the ingredients into it, except fish. Blend the mixture well until you get a smooth paste-like consistency. Place fish steaks into the spiced marinade, and marinate for around 30 minutes. After the marination is done, wrap the marinated fish in a banana leaf nicely and ready the steamer. Steam the fish until it is completely cooked through. Place the cooked fish on a serving plate and pour the cooking liquid over the top. Squeeze some lemon and garnish with coriander and serve hot.