====== Mornay Mushroom Sauce ======

===== Ingredients =====

  * 2 tablespoons butter
  * 2 tablespoons all-purpose flour
  * 1 1/2 cups milk
  * 1 cup shredded Gruyère or Swiss cheese
  * Salt and pepper to taste
  * 1/2 cup grated Parmesan cheese
  * 1 cup sautéed mushrooms (you can use a variety like cremini or button mushrooms), chopped
  * 1 tablespoon chopped fresh parsley (optional, for garnish)

===== Instructions =====

  - In a saucepan over medium heat, melt the butter.
  - Add the flour and whisk constantly to form a roux. Cook for a minute or two until the roux is lightly golden.
  - Gradually whisk in the milk to the roux, ensuring there are no lumps. Continue whisking until the mixture thickens.
  - Reduce the heat to low, and add the shredded Gruyère or Swiss cheese to the sauce. Stir until the cheese is melted and the sauce is smooth.
  - Season the sauce with salt and pepper to taste.
  - Add the grated Parmesan cheese and continue stirring until it is fully melted and incorporated into the sauce.
  - Stir in the sautéed mushrooms, ensuring they are evenly distributed in the sauce. Cook for an additional 2-3 minutes to heat the mushrooms through.
  - If desired, garnish the sauce with chopped fresh parsley.