Put the chicken breasts in a small pan of cold water over a medium heat. Slowly bring to the boil, skimming off any scum that rises to the surface. Reduce the heat and simmer for 12-15 minutes until cooked through. Remove with a slotted spoon, set aside to cool slightly, then shred into bite-size pieces.
Mix the creamy cheese with the lemon zest, juice and 2 pinches of chilli flakes, season and set aside.
Cook the pasta in boiling salted water for 8-10 minutes until al dente. Meanwhile, cook the vegetables according to the packet instructions. Drain the pasta, reserving a couple of tablespoons of the cooking water, then return to the pan with the water, over a low heat. Stir through the creamy cheese and chicken, let them warm through for a minute, then add the vegetables. Season with plenty of pepper and a pinch more chilli flakes, if you wish, then divide between 2 plates and serve.
This combo works well with any pasta. Refrigerate the chicken cooking liquid to use in soups.