Broccoli Cheese Puff

1 cup sliced fresh mushrooms
1 tablespoon butter
1 package (3 ounces) cream cheese, softened
6 eggs
1 cup  milk
3/4 cup biscuit/baking mix
3 cups frozen chopped broccoli, thawed
 2 cups (8 ounces) shredded Monterey Jack cheese
1 cup (8 ounces)  cottage cheese
1/4 teaspoon salt

 In a small skillet, saute mushrooms in butter until tender; set aside. In a large bowl, beat the cream cheese, eggs, milk and biscuit mix just until combined. Stir in the broccoli, cheeses, salt and mushrooms. Pour into a greased round 2-1/2-qt. baking dish. Bake, uncovered, at 350° for 50-60 minutes or until a thermometer reads 160°. Let stand for 10 minutes before serving.