3 large sweet potatoes, peeled and shredded (about 4-1/2 cups)
2 teaspoons prepared horseradish
2 cups shredded sharp cheddar cheese
1 cup panko bread crumbs
In a large saucepan, saute onion and garlic in butter; cook until tender. Whisk in the flour, salt and pepper until blended. Gradually add the milk. Bring to a boil; cook and stir for 2 minutes or until thickened. Remove from the heat; stir in the sweet potatoes and horseradish.
Transfer half to a greased 9-in. square baking dish. Combine cheese and bread crumbs; sprinkle half over the sweet potato mixture. Repeat layers. Bake, uncovered, at 400° for 30 minutes or until bubbly.