1.Preheat a covered barbecue with all burners on low and hood closed until temperature reaches 220°C/425°F, or follow manufacturer’s instructions.
2.Peel pumpkin; cut pumpkin crossways into 2cm slices, then cut each half moon-shaped slice into four pieces.
3.Combine cumin, paprika and oil in a small bowl. Toss pumpkin with half the spice mixture in a medium ovenproof dish; season. Add onion wedges to dish. Place dish on barbecue; turn burners off underneath dish, leaving the other burners on low. Cook pumpkin and onion in covered barbecue for 40 minutes or until almost tender.
4.Combine chorizo, chickpeas and chilli in a large bowl with remaining spice mixture. Add to baking dish with pumpkin; cook in covered barbecue for 20 minutes or until chorizo and pumpkin are browned and tender.
5.Meanwhile, make sherry vinegar dressing. Place ingredients in a screw-top jar; shake well. Season to taste.
6.Drizzle dressing over salad, then add herbs; toss gently to combine.
Disposable aluminium baking dishes available from supermarkets are great to use for cooking on the barbecue. This recipe can also be roasted in a 200°C/400°F oven for the same cooking time. Serve this salad in small dishes as tapas or on a large platter as an accompaniment to a main course.