Mustard Sauce (Excellent With Corned-Beef)

Grrrrrgh!
Course : Sauces
From: HungryMonster.com
Serves: 8
 

Ingredients:

1 1/2 tablespoons butter
1 large egg
1/2 cup brown sugar -- packed
1/4 cup granulated sugar
1/4 cup prepared mustard
1/4 teaspoon salt
1/8 teaspoon pepper
3/4 cup cider vinegar
 

Preparation:

Melt butter in small saucepan. Remove from heat, set aside to cool. In small bowl, with rotary beater, beat egg, sugars, mustard, salt, and pepper untill well combined. Beat in vinegar, stir mixture into cooled butter, mix well. Over medium heat, bring to boiling, stirring. Reduce heat; simmer 3 minutes. Serve hot, along with "old Fashion Corned-Beef and Cabbage".