This recipe for Mushrooms Florentine is delicious on pasta or rice.
Preheat oven to 350 degrees F.
Place 2 tablespoons of the butter in a large skillet over medium heat. Add the mushrooms and cook until browned, browning the cap sides first.
In a large bowl, Stir the salt, onion and remaining 2 tablespoons butter with the spinach.
Line a 10 x 7-inch casserole with the spinach mixture. Sprinkle 1/2 cup of the cheese over the spinach.
Arrange the browned mushrooms over the cheese; season with the garlic salt and top with the remaining 1/2 cup cheese.
Bake for 20 minutes or until the cheese is melted and browned. Serve hot over pasta or rice.