Bitter ballen are croquette-like meatballs which are very popular in the Netherlands.

3 tbsp. butter
4 tbsp. flour
1 c. milk
1 tbsp. very fine minced onion
1 tsp. Worcestershire sauce
1/2 tsp. grated nutmeg
1/2 tsp. salt
1 tbsp. chopped parsley, fine
1 1/2 c. finely chopped cooked meat
Bread crumbs
2 egg yolks, beaten with 2 tbsp. water
Fat for frying
Mustard

Melt butter, stir in flour and add the milk. Cook, stirring constantly, to make a very thick sauce. Add onion, meat, parsley, nutmeg, salt and Worcestershire sauce. Simmer for 5 minutes, stirring constantly. Spread mixture on cookie sheet to cool. Shape into small balls (1" to 1 1/2" diameter). Roll in bread crumbs. Dip in egg mixture, making sure they are completely covered. Roll again in bread crumbs. Let them stand for 1 hour until completely dry. Deep fry until golden brown and drain on paper towels. Serve with mustard.