Cook the pasta following pack instructions and drain well, reserving a mug of the pasta cooking water. Set aside.

While the pasta is cooking, heat the oil in a frying pan over a medium-high heat and fry the pancetta or bacon for 3-5 mins until golden and crispy. Remove to a plate using a slotted spoon and set aside. Add the leeks to the pan, along with the butter and sugar, and fry for 5 mins until softened and slightly caramelised. Add most of the gorgonzola, and stir until slightly melted. Toss in the cooked pasta with a splash of the reserved cooking water along with most of the pancetta.

Season to taste and serve with the remaining gorgonzola and pancetta scattered over the top.