Garlic puree: Place the garlic cloves in a saucepan of boiling water. Bring to a boil, drain and repeat 3 times. Once fairly soft, you will find they peel very easily. Place cloves in the blender and blend until thick, smooth, and glossy. Set aside.
Parsley sauce: Wash the parsley. Pick the leaves off, place in boiling water, and simmer gently for 3 to 4 minutes. Run under cold water to stop further cooking. Place leaves in a blender and blend to a paste. Squeeze the puree through a sieve, place in a saucepan with a little water, enough to obtain the consistency of a coulis. Cook until it covers the back of a spoon smoothly and evenly. Set aside.
Frogs legs: Remove two muscles from the shin part of the leg. Roll the legs in the bowl of plain flour mixed with salt and ground black pepper. Fry gently in the goose fat and butter in a shallow saute pan. Cook the legs until crispy and slightly browned on the outside, about 3 to 5 minutes. Place on a kitchen towel to absorb the excess grease.
This dish is best served on a white plate, as it is so colorful. Place a layer of the parsley puree all over the plate. Create a small mound of garlic puree in the middle. Uniformly place the frogs' legs around the garlic in a circle. About 12 frogs' legs per person is recommended.