Heat the oil in a large casserole dish or saucepan over a medium heat. Add the sausages and cook for 10 minutes, turning regularly, until browned. Meanwhile, peel & chop the vegetables.
Remove the sausages from the pan using tongs or a slotted spoon, and set aside.
Add the red onion, garlic, butternut squash, sweet potato and apples and cook for 10 minutes, stirring regularly.
Return the sausages to the pan and add the stock and herbs. Season to taste with salt and pepper. Bring to the boil, reduce the heat and simmer for around 30 minutes or until the vegetables are cooked.
Serve with salad or green vegetables, and bread if desired.