- 1/4 cup butter
- 20 button mushrooms, finely chopped
- 1/4 cup finely chopped onion
- 2 cups torn spinach leaves
- 1 teaspoon dried parsley
- 1/4 teaspoon garlic salt, or to taste
- 1 pinch ground black pepper, or to taste
- 1/2 cup shredded sharp Cheddar cheese
- 1 cup sour cream
- 1 cup shredded sharp Cheddar cheese
- Preheat an oven to 350 degrees F (175 degrees C).
- Heat the butter in a skillet over medium heat. Stir in the mushrooms and onion; cook and stir until the mushrooms have softened and the onion is translucent, about 7 minutes. Stir in the spinach, parsley, garlic salt, and pepper. Continue cooking until the spinach has wilted, about 3 minutes. Remove from heat and stir in 1/2 cup of Cheddar cheese. Cool for 5 minutes. Stir in the sour cream, then spread mixture into an 8×8-inch baking dish. Sprinkle 1 cup of Cheddar cheese on top.
- Bake in the preheated oven until the cheese has melted, about 20 minutes.