According to the BBC site:
1 large or 2 small butternut squash, cut into quarters lengthways, seeds removed
olive oil, for drizzling
2 tbsp butter
salt and freshly ground black pepper
few sprigs fresh thyme, leaves only, plus few sprigs fresh thyme, left whole
Preheat oven to 180C/350F/Gas 4.
Place the squash in a roasting tin, cut-sides up.
Drizzle over the olive oil and dot with the butter. Season, to taste, with salt and freshly ground black pepper, then scatter over the thyme leaves and the whole sprigs of thyme.
Roast in the oven for 45-50 minutes, or until the squash is tender and has turned golden-brown in places.