Heat oil in a saucepan, add onion and sauté for 1-2 minutes to soften. Stir in Five Tastes Curry Paste and cook for 1 minute or until fragrant. Add stock and pumpkin, cover and simmer for 10 minutes.
Remove from heat and puree. Add coconut milk, fish sauce and palm sugar. Return to heat, stirring until just boiling.
Serve garnished with baby corn and coriander.