Creamy Macaroni and Cheese

INGREDIENTS

• 1/2 cup butter or margarine
• 1/2 cup all-purpose flour
• 1/2 teaspoon salt
• 1/2 teaspoon ground black pepper
• 1/4 teaspoon ground red pepper
• 1/4 teaspoon granulated garlic
• 2 cups half-and-half
• 2 cups milk
• 2 (10-ounce) blocks sharp Cheddar cheese, shredded and divided
• 1 (10-ounce) block extra-sharp Cheddar cheese, shredded
• 1 (16-ounce) package elbow macaroni, cooked