SERVES: 8

INGREDIENTS
100 g butter, plus more for baking dish
450 g macaroni
65 g flour
1 l whole milk
1 1/2 tsp. salt
Freshly ground black pepper
1 tsp. mustard powder
300 g grated cheddar
200 g grated Gruyère
150 g grated Parmesan
125 g bread crumbs
3 tbsp. extra-virgin olive oil
Freshly chopped parsley, to garnish

DIRECTIONS

1. Preheat oven to 190°C (170ºC fan). Butter a 23 x 33cm baking dish. In a large pot of salted, boiling water, cook macaroni until al dente. Drain and set aside.
2. In a large saucepan, melt the butter. Sprinkle over flour and cook until slightly golden, 2 to 3 minutes. Pour in milk and whisk until combined. Season with mustard powder, salt, and pepper. Let simmer until starting to thicken, about 5 minutes.
3. Remove pan from heat and whisk in cheddar, Gruyère, and 50g Parmesan. Continue whisking until melted and smooth. Stir in cooked macaroni and transfer to prepared baking dish.
4. In a small bowl, combine remaining Parmesan with bread crumbs and oil. Sprinkle mixture over macaroni, then season with more black pepper.
5. Bake until bubbly and golden, 25 to 30 minutes.
6. Garnish with parsley before serving. Let sit 10 minutes before serving.

https://www.delish.com/uk/cooking/recipes/a28830973/3-cheese-mac-recipe/