Remove the sausages from their casings and place in a bowl. Finely chop half of the basil leaves and add to the bowl along with a generous amount of black pepper. You could add some finely grated Parmesan now, too, or any other flavours you want. Wet your hands, then roll teaspoons full of the mixture into small balls. Set aside. Heat a tablespoon of olive oil in a wide frying pan. Add the meatballs and cook on a medium heat, turning regularly until cooked in the centre and nicely browned on the outside. You may have to cook these in batches.

Place a tablespoon of olive oil in a large saucepan. Sauté the chopped onion. After five minutes, add the mushrooms. Cook for another five minutes and pour over the wine. Increase the heat and stir gently, letting the alcohol evaporate. You only want the flavour to remain. After a few minutes add the tinned tomatoes, Dijon mustard and water. Crush the fennel seeds roughly and add to the sauce along with a sprig of basil. Leave the sauce to simmer and reduce slightly. Taste for seasoning and add a little sugar if the tomatoes are too bitter. Stir through the tagliatelle and place the lid on. Arrange the meatballs on top of the bubbling sauce or keep them warm in the oven. Leave to cook for three minutes until the pasta is al dente. Divide the pasta and meatballs between six bowls. Garnish with the remaining torn basil leaves and a generous drizzle of olive oil.