Heat oven to 400 degree. Line a baking sheet with tin foil or a silicon mat.
Prick sweet potatoes several times with a fork and place on baking sheet. Roast in oven for 45-50 minutes or until tender when priceked with a fork. Let cool to touch.
When cool, peel away skin and add sweet potato meat to a blender or food processor.
Add in 1/2 cup coconut milk and coriander to the blender and puree for 1-2 minutes or until smooth. If puree is too thick, add in additional coconut milk or water in 1/4 cup increments until you have reached your desired consistency.