Preheat the oven to 180C.
Soften the onion in a pan on a low heat for 5 minutes, then add the garlic and cook for a further two.
Add the leek and the sausages. Cook on a low heat browning the sausages for 5 minutes.
Add in the lardons and cook for a further two minutes, before adding the cider, stock, mustard and vinegar.
Add in the pasta and simmer for 10 minutes on a low heat until most of the liquid has reduced and the pasta is al dente. You may need to add water as it simmers, depending on how big your pan is.
Add in the courgette, tomatoes and the mushrooms and cook for a further 2 minutes.
Stir through the creme fraiche and transfer to an oven proof dish. Sprinkle with cheese and bake for 15 minutes.
Dish up and devour!