1 butternut squash, unpeeled, halved, seeds scraped out, sliced into 2.5cm/1in x 2.5cm/1in cubes
1 onion, roughly chopped
500g/1lb 2oz sweet potatoes, unpeeled, cut into 2.5cm/1in thick rings
salt and freshly ground black pepper
1 tsp ground cinnamon
Β½ tsp ground nutmeg
60ml/2fl oz olive oil
1.5 litres/2 pints 13fl oz vegetable stock
250ml/9fl oz buttermilk
125g/4oz blue cheese, crumbled
125ml/4oz marsala wine