PASTA Bring a pot of salted water to a boil for the pasta. Cook the pasta until al dente, 10-12 minutes. Drain, reserving the pasta water, and toss through a drizzle of olive oil.
TOAST Place the pine nuts in a pan over medium heat. Toast until golden brown, 3-5 minutes (shifting occasionally). Remove from the pan and set aside. Return the pan to medium-high heat with 20g of butter and a drizzle of oil. Once melted, add the breadcrumbs and fry until lightly toasted and golden, 1-2 minutes. Remove from the pan and mix through the lemon zest (to taste).
LEEKS Roughly slice the rinsed leeks. Return the pan to medium heat with a drizzle of oil. When hot, fry the sliced leeks until caramelised, 8-10 minutes (shifting occasionally). At the halfway mark, add a sweetener (to taste). In the final 1-2 minutes, add the grated garlic. Remove from the pan, season, and cover.
GREEN Return the pan to medium-high heat with a drizzle of oil. When hot, fry the rinsed green beans until starting to char, 5-6 minutes (shifting occasionally). Remove from the pan, season, and cover.
CHEESE SAUCE Placeapotovermediumheatwith40gofbutter. Once melted, vigorously whisk in the cornflour to form a roux. Cook out the flour, 1-2 minutes (stirring constantly). Slowly whisk in the milk and 200ml of the reserved pasta water. Simmer until slightly thickening. Add the grated cheese and stir until melted. Mix in the cooked pasta and the caramelised leeks. Remove from the heat, loosen with a splash of water if it’s too thick, and season.
TIME TO EAT Plate up the creamy mac ‘n cheese and sprinkle over the zesty breadcrumbs. Side with the charred green beans and top with the cheese ribbons. Drizzle over the truffle oil, scatter over the toasted pine nuts, and squeeze over the lemon juice (to taste).