Sweet potato and peanut butter soup

This is another of my adjustable-spicy recipes. 1/2 tsp of chili paste worked well, but doubling it would be fine.

Mats
1 Tb olive oil
1 leek, white parts only
1 1/2 Tbsp tomato paste
1 1/2 Tbsp creamy peanut butter
1/2 tsp chili paste
1 clove garlic, crushed
1c spinach
1/2 tsp tumeric
1/4 tsp cumin
1 sweet potato, peeled and cut into 1 inch chunks
1 1/4c stock. I used a combination of vegetable stock and mushroom stock, because that's what I had on hand.
3/4c water

In a medium pot, heat the oil over medium heat. Add the chopped leek and crushed garlic. Cook on medium for 5 minutes until the leek begins to soften
Add the sweet potato, tomato paste, peanut butter, chili paste, tumeric, cumin, water and stock. Stir well so the peanut butter is all dissolved.
Cover and cook for 20 minutes. Test the sweet potatoes - they should fall apart when you poke them with a fork.
Blend the soup, either in a food processor or a blender. Add a little water (1/4 c at a time) if your blender begins to seize up.
Return the soup to your pot and turn the heat to medium low
Stir in the spinach and cook 3 or so minutes until the spinach starts to wilt