Crock-pot Ravioli Casserole 1½ lbs. lean ground beef 1 onion, chopped 1 clove garlic, minced 1 (15 oz.) can tomato sauce 1 can stewed tomatoes 1 tsp. oregano 1 tsp. Italian seasoning salt/pepper 10 oz. frozen spinach, thawed (I used fresh spinach) (optional) 16 oz. bowtie pasta, cooked ½ cup parmesan cheese, shredded 1½ cup mozzarella, shredded