Melt butter in saucepan over low heat.
Blend in flour, salt and pepper. cook over low heat, stirring until mixture is smooth and bubbly.remove from heat. stir in milk.heat to boiling, stirring constantly.
Boil and stir 1 minute. prepare thick white sauce. stir in meat, 1 tablespoon minced onion and the parsley.
Season with salt and pepper. spread mixture in ungreased square pan, 8x8x2 inches but you want to use a shallow pan to the mixture can completely cool to make it easier to handle.
Cover and chill at least 2 hours. mix egg and water. shape croquettes and dip in egg, and then breadcrumbs
Chill again. heat oil and fry croquettes for 2 minutes or until light brown.
Drain and keep warm until serving time.