Sausage and spinach spaghetti

Method

1. Bring a large pan of water to the boil, then add the spaghetti and cook for 9-10 minutes or until al dente. Drain, reserving 50ml of the pasta water.
2. Meanwhile, finely slice the onion and garlic and roughly chop the sausages into bite-size pieces. In a large frying pan, heat the oil over a medium heat. Add the onion and gently fry for 3-4 minutes. Add the garlic and sausages and cook for 2 minutes, then add the mustard and spinach. Cook for 1-2 minutes, then stir in the crème fraîche.
3. Zest the lemon, then stir into the sauce along with the pasta and reserved water. Season with salt and freshly ground black pepper to taste, then divide among 4 bowls and serve topped with a grating of parmesan.