Onions Au Gratin Recipe
- 1/4 cup butter
- 6 yellow onions, halved and sliced 1/2 inch thick
- 1/2 cup beef broth
- 1/2 cup heavy cream
- 2 tablespoons all-purpose flour
- 1/4 teaspoon salt
- 1/8 teaspoon pepper
- 1/2 cup shredded Swiss cheese
- 1/2 cup grated Parmesan cheese
step 1: Preheat the oven to 350 degrees F (175 degrees C). Grease an 8 inch square baking dish.
step 2: Melt the butter in a large skillet over medium heat. Add onions; cook and stir until tender, about 5 minutes. Transfer to the prepared baking dish. In a medium bowl, stir together the beef broth and flour until smooth. Mix in the cream and season with salt and pepper; pour over the onions. Sprinkle Swiss cheese and Parmesan cheese over the top.
step 3: Bake for 25 to 30 minutes in the preheated oven, until cheese is golden brown and the sauce is bubbly.