After cooking a piece of skin on fish, remove fish from pan and set aside to rest. Deglaze the same pan with juice from half a lemon.
Add 2 tablespoons of butter to pan and gently cook till melted.
Add crushed garlic and cook for one minute.
Add lemon zest, red pepper flakes, chopped parsley and cook for two minutes.
Season with salt and pepper and serve over fish.