Heat oven to 200C/180C fan/gas 6. Tip the pumpkin into a large roasting dish. Toss in the oil, season and roast for 40 mins, stirring once.
Mix the oil and mustard in a large salad bowl with salt and black pepper to taste.
Peel the oranges using a serrated knife and removing all the pith. Do this over the salad bowl so you catch all the juice. Segment the oranges with the knife to remove all the membrane, adding the segments to the bowl with the juice as you go.
Toss the pumpkin, spinach, watercress and chunks of cheese with the oranges and dressing until they’re all evenly coated.
Serve immediately, with gluten free bread to mop up the juices.