In a medium saucepan, melt butter, stir in flour. Add milk and cream and whisk until sauce is thick and bubbly. Mix in the cheese. Blend well. Stir in egg yolks. Season to taste.
Spread mixture over a greased square dish to a thickness of 1 inch. Cool 1/2 hour.
Cut into 2-inch by 1-inch pieces. Dust in flour, dip in egg white, and roll in fresh bread crumbs.
Deep fry until brown. Serve with tomato sauce and fried parsley.