From Food52.com. Make sure you use a good quality coconut milk, even if you have to order it. It makes a big difference in finished dishes. Makes about 3 quarts.

Heat a large soup pot over medium heat. Add oil, onion, and garlic, sautéing until the onion is starting to brown at the edges. Add the chili flakes, kale, sweet potatoes, and broth, and salt. Bring to a boil, reduce to a simmer, and cover, cooking until the sweet potatoes are fork tender, about 8-10 minutes. (Now is a good time to start cooking your rice!) Add the can of coconut milk, juice of one lime, and 1 tsp of sriracha, stirring to combine thoroughly. Taste and adjust the seasoning with more lime, sriracha, or salt. Put a scoop of rice in a soup bowl and ladle the soup over, and top with a few leaves of cilantro to serve.