Cheddar Mushroom Macaroni

4 cups (16 ounces) shredded cheddar cheese
1 can (10-3/4 ounces) condensed cream of mushroom soup, undiluted
1 cup mayonnaise
1 can (7 ounces) mushroom stems and pieces, drained
1 medium onion, finely chopped
1 jar (2 ounces) diced pimientos, drained
4 cups cooked elbow macaroni
1 garlic clove, minced, optional

In a large bowl, combine the first six ingredients; mix well. Stir in macaroni and garlic if desired.

Transfer to a greased 2-1/2-qt. baking dish. Cover and bake at 325° for 30 minutes or until heated through and cheese is melted. Makes 6-8 servings.