Sausage, mushroom and Breton cider stew

Method

1. Put a large heavy-bottomed pan or casserole dish over a medium heat, then add a splash of oil and the sausages. Cook gently until browned all over, then remove from the pan.
2. Add the butter to the pan and, once melted, add the onion, leek, garlic and mushrooms with a pinch of salt. Cook for 8 minutes, stirring regularly, until everything is nice and caramelised.
3. Add the flour and mustard, stir for a minute to coat everything, then add in the cider bit by bit, stirring to avoid lumps. Return the sausages to the pan (along with any juices) and bring to a boil, then turn down to a simmer for 10 minutes. Taste and season with salt and lots of freshly cracked black pepper. Add the chopped tarragon or parsley just before serving.