Pour the olive oil into a small saucepan and heat gently. Add the garlic, which you can either slightly crush, for a milder flavor, or slice or even finely mince for a much more assertive flavor. Keep the flame quite low. You are infusing the oil with the flavor of the garlic, which should not brown at all. (If you like you can remove some or all of the garlic at this point to avoid its flavor from becoming overpowering.) After about 5 minutes, add the anchovy fillets and butter and continue to simmer very gently for another 10 minutes, until the fillets have completely melted and the various flavors have been well amalgamated. Season with a bit of ground pepper.
