Ingredients
- 4 – 5 cups thinly sliced potatoes (about 6 – 8 medium potatoes)
- 4 Tbsp. butter
- 1/4 cup all-purpose flour
- 1 tsp. dried parsley flakes
- 1/2 tsp. dried thyme
- 2 tsp. salt
- 1/2 tsp. pepper
- 3 cups milk
- 1/4 cup finely chopped onion
- 1/2 lb. Italian sausage, casing removed, cooked, and crumbled
- 3/4 cup (packed) grated extra-sharp cheddar cheese (about 4 oz.)
- 3/4 cup grated Swiss cheese (about 4 oz.)
- 1/3 cup (packed) freshly grated Parmesan cheese
Preparation
Step 1
Preheat oven to 400°:F. Lightly butter a 10" nonstick sauté pan or similar size glass baking dish. Mix cheddar cheese, Swiss cheese, and parmesan in a small bowl.
In a saucepan, melt butter. Stir in flour, parsley, 1 tsp. salt, thyme, and 1/4 tsp. pepper until smooth. Gradually add milk and bring to a boil. Cook and stir for two minutes. Reduce heat to a low simmer.
Arrange half of potato slices in the prepared baking dish, overlapping slightly. Sprinkle with remaining 1 tsp. salt, 1/4 teaspoon pepper, and chopped onion. Scatter crumbled sausage and half of the cheese mixture over the top. Finish with remaining potato slices and the rest of the cheese mixture.
Pour the warm white sauce over the casserole and bake, uncovered, until potatoes are tender – about 20 minutes.