Choose white mushrooms with about a 1 to 1 1/2 inch cap and cut off the stems 1/4 to 1/2 inch below the caps. Cut into 4 or 6 pieces but do not slice. Immediately put the mushrooms, without cutting them, into acidulated water. Wash twice. Drain, wipe dry. Put into a frying pan with 1/3 the butter and the juice of 1/2 lemon. Cook over a medium heat, uncovered, stirring frequently until the water has evaporated and the mushrooms are cooking only in butter. Add the remaining butter, salt, pepper, brown over a very low heat until cooked, preventing the butter from darkening. To serve, sprinkle with parsley, with or without garlic.
