Preheat oven to 375°F

• 1500 g macaroni

Cook pasta al dente.

• 1 ¹⁄₁ cup (454 g) butter

Melt butter in saucepan.

• 1 ¹⁄₁ cup (250 g) all-purpose flour

Add flour, stirring together to make a roux.

• 15 cups (3.555 kg) milk

Slowly add milk, ensuring that the consistency stays thick.

• 3 onion, finely diced
• 3 tsp. dijon mustard
• 1800 g grated cheddar cheese
• 1 ¹⁄₂ tsp (9 g) salt
• ¹⁄₂ tsp black pepper
• ¹⁄₄ tsp nutmeg

Stir in onion, cheese, mustard, nutmeg, salt, and pepper.

Combine sauce with pasta.

• 450 g grated cheddar cheese

Sprinkle cheese on top.

• 2 ¹⁄₄ cups (279 g) bread crumbs
• 6 Tbsp (85 g) butter, melted

Toss butter and bread crumbs together and then sprinkle bread crumbs on top.

Bake at 375F for 30 minutes or until golden on top.