In a saute pan, put 1 tablespoon of butter, some olive oil, the onion and garlic. Saute lightly until the onion is transparent.
Add chopped livers and saute well over high heat for about 3 minutes or less.
Add white wine, salt, pepper, and parsley. As soon as wine has evaporated, add cream, 1 tablespoon butter, and the brown gravy, then bring to a boil, and simmer on low heat for about 1 minute.
Slice French bread very thin (use day-old bread) then toast it on a baking pan in the oven for 1 minute at 400 F.
Spread the liver mixture on the toasted bread to serve.
Garnish with grated white truffle, sauteed mushrooms, or chopped parsley.