Heat the butter and oil in a pan just large enough to hold your fish. When it starts bubbling a bit, lay the fish filets in it, salt and pepper the top of the fish and cook 2-3 minutes depending on how thick your fish is. Turn the fish over and cook until done, another 2-3 minutes and salt and pepper that side as well.

Put the fish on your serving dish (or directly on dinner plates), leaving the pan on the heat. Add the lemon juice and slices, capers, garlic and wine. Heat to a simmer and cook a minute to reduce the juices, then add the butter to melt and thicken the sauce. Pour over the fish and serve.