Shrimps Newburg

2 tb butter
2 tb all purpose flour
2 cups milk
salt and pepper to taste
4 tb sherry wine
1/2 tsp dry mustard
2 egg yolks, beaten
1 cup cream
2 lbs shrimps, boiled and cleaned

Melt the butter in skillet and add the flour. Add, constantly moving, the milk. Add the salt, pepper and mustard and move. Add the sherry. Cook the sauce in a special bain the Marie utensil, and cook, moving, for 20 minutes. Remove from heat and let stand for 5 minutes. Add the beaten egg yolks, with the cream. Add the shrimps. Heat for 3 minutes, but do not boil, or the sauce will curdle. Serve over white rice or mashed potatoes.