Remove chorizo from casing and cook in a large saute pan for about 4 minutes. Remove and set aside. Add sweet potatoes, garlic powder, cumin and olive oil to the pan and cook for 5 minutes. Add the onions and cooked chorizo back to the pan, and cook for another 5 minutes. Add the kale and cook until wilted - about 2 minutes. Remove from heat, add lime juice, and season with salt and pepper to taste before serving.