1. Heat the oil over medium heat. Add the sausages, cook until golden, and remove.

2. Add the onion and cook until softened. Add the mushrooms and cook for 5 minutes, then stir in the stock, apple, sage, and bay leaf.

3. Bring to a boil, then return the sausages. Reduce the heat, cover, and cook gently for 20 minutes, stirring often. The apple pieces should break down and thicken the sauce slightly. If they are still holding their shape, mash them with the back of a wooden spoon and stir in.

4. Mix the cream and mustards together in a bowl and season with salt and pepper. Pour into the casserole, increase the heat, and boil gently for 5 minutes, or until the sauce has thickened slightly.

Special Equipment: Large flameproof casserole.