Sauté the onions in 1 Tbsp olive or coconut oil until soft.
Add the Thai curry paste and garlic and continue to cook over low heat for 1-2minutes.
Add the pumpkin puree, chicken stock, and coconut milk, bring to a simmer. Season with salt and pepper.
Process until smooth in a blender. Taste and correct seasoning, add lime juice and fish sauce or vegan substitute. We like Cook's Illustrated fish sauce substitute recipe.
Reheat soup and add the Thai basil and fresh cilantro just before serving to taste.