Place the fish fillets in a flat baking dish and season with a little pepper. Chop the garlic and parsley and spread over the fish. Squeeze the lemon and mix well with the olive oil and salt, then pour over the fish as well. Pour half a glass of water over everything and cover the baking dish with a lid or aluminum foil.
Place in the oven at 200 ° C for between 15 and 30 minutes, depending on the thickness of the fillets.