Heat the ghee in a large pot over medium heat. Add the onion, garlic, and ginger, and stir fry for a few minutes until fragrant. Do not let the garlic burn or brown.
Add the curry paste, turmeric, and salt. Stir fry for another few minutes.
Add the sweet potatoes, 2 cups of broth, and the coconut milk. Simmer until the sweet potatoes are soft.
Allow to cool slightly, then transfer to a blender and puree until smooth and silky. The soup should be rich and thick so that it coats the back of a spoon. Add in more water or broth (I used ½ cup more) to thin out the soup as needed. Taste and add more salt if desired, or chili flakes (optional).
Finish with toppings, see below for suggestions.
by Fresh Planet Flavor
Toppings: peas, green onions, chives, cilantro, basil, red or green cabbage, asparagus, baby kale or spinach or mustard greens, shredded carrots, zucchini noodles (zoodles), bell peppers, mushrooms, spinach, broccoli, snap peas, bean sprouts... the list goes on!