In a large plate of a bowl combine the flour, salt and pepper. Dredge the fish in the flour mixture, then shake off the excess flour.
Preheat a frying pan and melt 2 tbsp of butter in it. Fry the sole in butter on medium heat for approximately 2 minutes on each side. Then remove from the pan and keep warm.
To the same pan add the remaining butter and let it melt and watch it turn slightly brown, then add the juice of half a lemon and slices of the other half, cook for a few seconds, then add the capers and return the fish back to the pan. Spoon the sauce all over the fish and take off the heat. Serve sprinkled with fresh parsley.