Take a large, wide pan for which you have a lid (a casserole dish is ideal) and place it over a medium heat. Add the oil and, when hot, add the sausages to the pan. Cook, turning gently, until browned all over. Transfer the cooked sausages to a plate and set aside. Keeping the pan on the heat, add the onions and garlic and cook, stirring every now and then, until they start to soften (4-5 minutes), then add the pancetta and cook for a few minutes longer, until the meat has browned. Lightly crush the bay leaves in your hands to release their aroma, then put them in the pan, then strip the leaves from the rosemary and thyme, chop roughly and stir in. Place the sausages back in the pan, then pour in the wine and season to taste with salt and pepper. Increase the heat until the pan is simmering, then put the lid on, turn the heat down as low as possible and leave to simmer gently for 30 minutes.

Next, stir in the mushrooms and continue to cook gently for 20 minutes more with the lid left off, so the liquid reduces slightly. Meanwhile, put the flour, mustard and softened butter into a small bowl and beat to a smooth paste, then set aside. When the 20 minutes are up, use a slotted spoon to lift the sausages and as much of the veg as you can out and into a warm serving dish. Whisk the mustard paste into the pan, a little at a time, and leave to simmer for a few more minutes, then stir in the redcurrant jelly until well combined. Return the sausages and veg to the pan and take it off the heat. Give everything a gentle stir together, then serve with your choice of accompanying veg.