1 1/2 pounds round red or Yukon Gold Potatoes, sliced
12 ounces sweet potatoes peeled and THINLY sliced
1/4 cup butter
1 medium onion, chopped
3 tablespoons flour
2 1/4 cups milk
1/2 cup grated Parmesan Cheese
1 tablespoon fresh tarragon OR 1/2 teaspoon dried tarragon, crushed
1/2 teaspoon salt
1/2 teaspoon black pepper
fresh tarragon (optional)
Preheat oven to 350 degrees. Grease baking dish.
Heat butter over medium heat. Add onion. Cook for about 5 minutes or until onions are tender, stirring frequently. Stir in flour, cook and stir for one minute. Add milk all at once. Cook until mixture is thickened and bubbly. Stir in Parmesan Cheese, the one tablespoon of fresh or dried tarragon, salt and pepper.
In a greased 2 quart shallow baking dish, arrange half of the round red or Yukon Gold potato slices and half of the sweet potato slices; alternating them in rows, if desired. Spoon half of the sauce over the potatoes. Arrange remaining potatoes over these layers in dish. Top with remaining sauce.
Cover and bake for 40 minutes. Uncover and bake about 30 minutes more or until potatoes are tender and sauce is golden brown. If desired, garnish with the additional fresh tarragon.
Makes 8 servings.