To precook the pasta
Precook the pasta in salted water for approx. 5 mins., drain, dip briefly in ice-cold water, drain.
Heat the oil in a non-stick frying pan. Sauté the shallot, brown the mince for approx. 5 mins., reduce the heat. Pour in the stock, simmer for approx. 10 mins. Combine the cornflour and milk, add to the chicken along with the sour single cream. Add the peas and spinach, simmer briefly, season.
Spread a little sauce over the bottom of the prepared baking dish. Add the rigatoni, pour the remainder of the sauce over the pasta, top with the mozzarella.
Approx. 30 mins. in the centre of an oven preheated to 200°C.