Clarify the butter: put half of the butter in a small saucepan, place it over low heat, let it melt until a kind of milk appears. Remove from heat, let it settle at the bottom of the saucepan, recover the melted butter like oil. Dry the soles, salt them, pepper them, flour them very lightly. Heat half of the clarified butter and oil in a large pan, brown 2 soles, 3 to 4 minutes on each side. Drain them, place them on a hot serving plate and set them aside. Repeat the same operation for the remaining 2 soles, place them on the plate with the others. Squeeze the lemon juice. Put the remaining butter in a saucepan, add the lemon juice, brown over medium heat. Sprinkle chopped parsley over the sole. Serve.