Creamy Sausage Pasta Bake

Make the sausage ragu. Heat the olive oil in a large deep frying pan or flameproof casserole over medium heat. Remove the sausage meat from the casings and add it to the pan in small pieces. Cook for 8-10 minutes, breaking it up lightly, until browned. Stir in the sliced garlic and cook for 1 minute, then add the chilli flakes, tomato puree, and red wine vinegar. Pour in the chopped tomatoes, bring to a gentle simmer, then reduce the heat and cook uncovered for 30 minutes until thickened.

Prepare the white sauce while the ragu simmers. Melt the butter in a saucepan over medium heat, then stir in the flour to form a smooth paste. Cook for 1 minute, whisking, then gradually add the milk a little at a time until smooth. Simmer gently for about 10 minutes, whisking occasionally, until lightly thickened. Season to taste and stir in the grated Parmesan. Remove from the heat.

Cook the pasta in a large pan of salted boiling water for 1 minute less than the package directions, about 9 minutes. Drain and return it to the pan. Stir in most of the white sauce, most of the sausage ragu, and most of the mozzarella until evenly coated. Transfer to a large baking dish, then spoon the remaining white sauce and ragu over the top. Scatter with the remaining mozzarella and a little extra Parmesan.