Horseradish Scalloped Potatoes Grand Prize Winner July – December 2005 Online Recipe Contest)

Number of Servings: 12

1 ½ C. (packed) grated extra-sharp cheddar cheese (about 8-oz.)
1/3 C. (packed) freshly grated Parmesan cheese (about 1 ¼-oz.)
4 Lb. russet potatoes, peeled, cut into ¼-inch thick rounds
2 tsp. salt
½ tsp. ground black pepper
½ C. finely chopped onion
3 Tbsp. all-purpose flour
4 Tbsp. (1/2 stick) butter
3 C. milk (2% or whole)
¼ C. prepared horseradish

Preheat oven to 400ºF. Lightly butter 13 x 9 x 2 glass baking dish. Mix cheddar cheese and Parmesan in small bowl. Arrange half of potatoes in prepared baking dish, overlapping slightly. Sprinkle with 1 tsp. of salt and ¼ tsp. pepper. Sprinkle onion over, then flour. Dot with 2 Tbsp. butter. Sprinkle half of cheese mixture over top. Top with remaining potatoes, 1 tsp. salt, ¼ tsp. pepper and 2 Tbsp. butter. Reserve remaining cheese. Pour milk into medium saucepan. Stir in horseradish and simmer for 5 minutes. Pour milk mixture over potatoes. Cover baking dish tightly with foil. Bake 45 minutes. Uncover dish. Sprinkle potatoes with reserved cheese mixture. Bake uncovered until potatoes are tender and cheese is deep golden brown, about 45 minutes longer. (Can be prepared 2 hours ahead. Let stand at room temperature. Cover and re-warm in 375ºF oven about 20 minutes.) Remove from oven; let stand 15 minutes before serving.