1. Preheat your oven to 160C fan-forced or 180C conventional.

2. Rub the pumpkin and onion with olive oil, season with salt and pepper and roast for one hour, or until cooked. Scoop out the pumpkin flesh once cool enough to handle.

3. In a wide-based pot, add the coconut oil, roasted onions, garlic and chilli and cook for three minutes, stirring. Add the tom yum paste and cook for a further minute. Add the pumpkin flesh, fish sauce, coconut water, water and sugar, bring to the simmer and cook for 20 minutes.

4. Add the lime juice and puree with a stick blender. Adjust the seasoning to taste with a little more fish sauce, if needed. Serve with pieces of young coconut flesh (if using), coriander leaves, a drizzle of coconut cream and a sprinkling of prawn floss.

Tips:

1. To make prawn floss, pound out some dried shrimp in a mortar, or blend, until powdery.

2. This soup freezes well. Once reheated, check the seasoning and freshen with some lime juice.

3. High-quality vacuum-packed crabmeat is available at many fishmongers. Simply drain, gently warm through and serve on the soup.