For the salsa, chop olives. Peel and chop lemon into small dice, discarding any seeds as you go. Combine olives, diced lemon, minced garlic and oregano leaves in a small bowl. Moisten with 4 tablespoons extra virgin olive oil. Leave to stand for the flavours to mingle while you cook the fish.
Heat a frying pan on a medium high heat. Season fish with salt on both sides. Add a splash of oil to the hot pan and cook fish for 3-5 minutes or until browned on the outside and cooked to your liking.
Divide fish between two plates. Spoon over the olive lemon salsa. Serve with cucumber or green salad on the side.