Preheat oven to 350 degrees. In a 2-quart saucepan, melt butter then incorporate flour to make roux. With a wire whisk slowly pour in milk, whisking vigorously to avoid lumps. Once milk is incorporated, sauce is made. Simmer for ten minutes to remove flour flavor. Finally fold in two pounds of grated Cheddar. Season with salt and pepper. In a large mixing bowl combine elbow macaroni with cheese sauce. Mix well. Pour into casserole pan and bake at 350 degrees for thirty minutes or until crunchy golden brown.