I have been making this for a very long time, if you have been to a retreat here it’s likely you have had this soup!
I don’t have a recipe or quantities as such - its that easy its not necessary and you can play around with what consistency and taste you like best.

You need:
Onions - chopped
Garlic - chopped
Sweet potatoes - chopped
Coconut milk
Stock
Salt and pepper
The rest is totally up to you, you could just use curry powder keep it really simple.
My usual mix is:
Mustard seeds
Black onion seeds
Cumin seeds
Turmeric
Before serving some garam masala and chopped coriander

I cook the onions and garlic until soft, then add in the spices and seeds, cook until you can smell them (not too hot) and then add the potatoes, stock and coconut milk. You need enough liquid to cover the potatoes (you can always add more if its too thick later)
When the potatoes are soft blend with a hand blender - that’s it!
Add the garam masala and the coriander and enjoy.