Crumble the stock cube into a saucepan then, using your judgement, pour in just enough water needed to cover the pasta. Bring to the boil over a high heat then add the pasta. Cook according to the instructions on the packet, or until al dente. There should be a thick starchy sauce left over when the pasta is cooked, do not throw this out.
Meanwhile fry the bacon and chicken together in a frying pan over a medium heat until the chicken is no longer pink in the centre. Add to the pasta and toss together. Just prior to serving mix in the cheeses and the spinach, allowing it to wilt. Transfer to a serving bowl and serve immediately.
You can use leftover cooked chicken in this recipe, just add in step 2 when tossing the bacon and pasta together.