1 Bring a large pan of salted water to a rolling boil and add the linguine. Cook for around 10-12 minutes, or until tender but still slightly al dente. Drain then toss with one tablespoon of olive oil and set aside.
2 Heat the remaining olive oil in a large pan over a medium heat. Add the chicken slices, season with salt and pepper and cook for 6-7 minutes per side, or until thoroughly cooked through. Remove from the pan and set aside.
3 Melt the butter in the same pan. Add the leeks and cook for 5-6 minutes until softened. Add the garlic and cook for one minute.
4 Add the lemon zest and Mascarpone and heat through. Stir in the grated Parmesan, lemon juice and some salt and pepper, to taste. Cook for 2-3 minutes until very hot.
5 Add the pasta and chicken to the sauce and toss together to coat, adding a splash of the pasta cooking water if needed to loosen the sauce.
6 Divide between bowls and serve topped with extra Parmesan, some fresh parsley & lots of freshly cracked black pepper.