Mashed Potato Gratin - cooking recipe

Ingredients

3 lbs russet potatoes, cut into small pieces
1/4 cup butter or 1/4 cup margarine
3 egg yolks
1 teaspoon salt
1 cup milk
1 1/2 cups shredded swiss cheese (6 oz.)
chopped fresh parsley, if desired

Preparation

Heat oven to 350. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. In 4-quart saucepan or Dutch oven, place potatoes; add enough water to cover potatoes by 1 inch. Heat to boiling over high heat. Reduce heat to medium-low; simmer uncovered 20 minutes or until potatoes are tender and can be easily pierced with fork.
Drain potatoes; return to saucepan. Add butter; mash with potato masher until creamy. Stir in egg yolks, salt, milk and 1 cup of the cheese. Spread potato mixture evenly in baking dish. Sprinkle with remaining 1/2 cup cheese.
Bake 30 minutes or until edges are light brown. Sprinkle with chopped parsley.