Eh, don’t want to delete and redraft now, but when I say half, I mean cut it into two pieces, like a box and a lid. You could do 50/50, but it’s messier to stuff
When the rice is ready, oil a pan just large enough for the squash. Finely chop some fresh herbs (here parsley and mint, but experiment) and spring onions, stir into the rice. Fill the bottom half of the squash with rice and herbs, use the top as a lid (I score mine) and roast at 175 C for at least an hour or until the squash is soft.