Heat oven to 200C/180C fan/gas 6.
Tip the onion, squash and chestnuts
into a roasting tin with the oil, chopped
sage and seasoning, then toss well with
your hands. Roast for 20 mins or until the
edges of the squash start to tinge brown.
If your oven is full, you can simply fry the
lot together in a large frying pan.
Add the rice and stir to coat it, then tip
the lot into a saucepan. Add the stock
and stir well. Bring to a simmer and cook
for 20-25 mins or until the rice is tender
and the stock absorbed. Add cheese, if
using, and tip into a baking dish. You can
now cover and chill the stuffing for up to
a day. To finish, heat grill to high, then
cook until the top is browned and crisp
and the stuffing is hot through.