Cheese Croutons

4 slices firm bread
    (1 or 2 days old)
1 egg yolk
2 tablespoons butter
1/4 cup grated Parmesan cheese

Put bread onto a cookie sheet. Toast on one side under the broiler. Blend remaining ingredients. Turn slices over and spread with the cheese mixture. Cut into squares. Bake at 350 degrees F until golden brown.