Peel and finely slice the garlic, pick the thyme leaves, and clean and tear up the mushrooms. Shred up the leftover ham or turkey.
Cook the pasta in a pan of boiling salted water according to the packet.
Heat a little oil in a large pan, add the garlic and cook for 1 minute, until golden. Add the thyme, mushrooms, sea salt and black pepper and fry for 5 to 8 minutes.
Stir in the ham or turkey, and continue to cook for 5 minutes, so everything gets some colour. Stir in the crème fraîche and remove the pan from the heat. Drain the pasta once cooked – saving a mugful of the cooking water – and let it cool slightly. Toss the pasta with a little oil, then stir into the sauce. Add a little cooking water to loosen, if needed.
Stir in the spinach, add a good grating of Parmesan, squeeze in the lemon juice, then season to taste before serving.