– 4 tablespoons unsalted butter – 1 peeled and small diced yellow onion – 4 finely minced cloves of garlic – 4 tablespoons all-purpose flour – 6 cups whole milk – 3 cups shredded sharp cheddar – 3 cups shredded white cheddar – 3 cups shredded American cheese – 1 ½ pounds macaroni noodles – 3 large eggs – sea salt and fresh cracked pepper