Cook the gnocchi in a pan of salted water following pack instructions. Drain and set aside.

Meanwhile, heat the oil in a large frying pan and fry the onion over a medium heat for 8 mins, or until softened and turning golden brown. Squeeze the sausagemeat out of the skins and into the pan, breaking it up with a wooden spoon. Cook for 5 mins until golden brown. Stir through the sprouts and cook for a further 5 mins until softened. Add the stock and mustard, and bring to the boil. Stir through the crème fraîche and parsley. Season. Tip in the gnocchi, tossing with 100ml water to loosen the sauce, and bring to a simmer for 3 mins. To serve, sprinkle with the extra parsley and parmesan, if you like.