Duchess Potatoes

4 cup mashed potatoes, heated
1/4 cup melted butter
2 egg yolks, beaten
1 teaspoon Dijon-style mustard
Salt and white pepper, to taste

Combine all the ingredients in a bowl and stir to thoroughly combine. Make mounds or patties on a greased baking sheet and decorate with a fork if desired. Alternately, you may pipe the mixture, using a pastry bag with a fluted tip, into any shapes you desire. Bake in a preheated 400 degrees F oven until golden brown.