Put the frozen Frog legs in a mixture of 50/50 milk and water and place them in the fridge for 4 hours. This will make the legs extra tender. If the Frog legs are fresh, leave them in the fridge for 2 hours in the milk/water mixture before to cook them
Mince the garlic and finely chop the parsley
Dry the legs with kitchen paper
Add flour in a deep plate and roll the frog legs in the flour until completely covered
Using a frying pan or a wok, heat 2 tbs of butter and 2 tbs of olive oil
Fry (in several small portions) the legs on both sides until cooked through. You may have to add some butter and olive oil in between each portion if it has dried out.
Meanwhile melt 4 tbsp of butter in a pot over medium/low heat and add the garlic
Let the garlic simmer at very low heat for several minutes in the butter until it gets tender.
Add the parsley to the butter/garlic and keep simmering for another minute before to add all the fried frog legs. Add salt and pepper, turn them carefully in the garlic/parsley butter and serve.