Onion Gratin

Ingredients

• 2 large onions, thinly sliced
• 2 tablespoons butter
• 1/4 cup all-purpose flour
• 2 cups milk
• 1 teaspoon salt
• 1/2 teaspoon freshly ground black pepper
• 1/2 cup grated Parmesan cheese
• 1/2 cup shredded Gruyere cheese

Directions

1. Preheat oven to 375 degrees F (190 degrees C). Grease a 9-inch baking dish.
2. In a medium bowl, mix together the Gruyere cheese, Parmesan cheese, pepper and salt; set aside.
3. In a medium saucepan over medium heat, whisk together the milk and flour until smooth. Cook, stirring constantly, until thickened and bubbly; remove from heat and set aside.
4. Melt butter in a large skillet over medium heat; add onions and cook until softened and lightly browned, about 10 minutes.
5. Spread half of the onion mixture into the prepared baking dish; top with half of the cheese mixture. Pour half of the milk mixture over top; repeat layers once more with remaining ingredients.
6. Bake in preheated oven for 30 minutes or until golden brown on top and bubbly around edges. Let stand for 5 minutes before serving. Enjoy!