Place the pasta, courgette, garlic, mushroom, thyme, a sprinkling of salt and pepper and stock in a large pot and bring to a boil. Simmer for 20 minutes until the liquid has been absorbed and the pasta is cooked.
While the pasta is cooking heat the grill to medium high. When the pasta is finished cooking remove it from the heat and tear the mozzarella and prosciutto over the top of the pasta. Place under the grill for 5 minutes until the cheese is melted and the prosciutto is a little crispy. Serve sprinkled with a little grated parmesan.