In a pan heat the oil and sear the fish for 2-3 minutes per side. Transfer to a plate and keep warm.

Return the pan to the heat and fry the onions and garlic for 4-5 minutes.

Add the cream sauce, capers, green olives and herbs and cook for 2-3 minutes. Return the fish to the pan and cook for 4-8 minutes, depending on the thickness of the fish. Squeeze the fresh lemon over the top before serving.