I've made this recipe a million times. I absolutely love it! It's very similar to a peanut satay sauce, but in soup form.
For non-vegans, you can also add cream or parmesan cheese for a silky texture. (huh, bet almond milk would be good. gotta try that!)

Gluten Free Vegetarian Soups: Sweet Potato Peanut Soup Recipe | Book of Yum

Curry Sweet Potato Peanut Soup

1 tbsp olive oil
1 large onion, chopped
1 clove garlic, chopped
1 28 oz can tomatoes
5 cups vegetable broth (i like bullion)
2 lg sweet potatoes, peeled and cubed
3/4 cup natural 100% peanut butter (or soy butter, or sunflower butter etc.)
1 tbsp. curry powder
1/4 tsp cayenne (I actually toss a couple dried chilis in there for an extra kick)
salt to taste

Cook onion and garlic in heated olive oil over medium heat until softened, covered.
Throw in your sweet potato cubes and then your tomatoes and broth. Bring everything to a boil and then lower to a simmer, cooking for around 30 minutes or until sweet potato cubes are soft.
Stir in everything else, letting the peanut butter dissolve. Take off burner, let cool, and begin putting in blender in batches. Put your creamy soup back in a pot and reheat it on the stove if necessary.
Enjoy yummy, healthy, and inexpensive seasonal gluten-free soup!