Heat the oil in a large pot over medium-high heat. 

Add the carrots, celery, onion, and salt and cook, stirring occasionally, until softened but not brown, about 5 minutes. 

Add the curry powder and cook, stirring continuously, for 30 seconds, being careful not to let the spices brown.

Add 5 cups water, sweet potato, coconut milk, tomatoes, and chickpeas to the pot. 

Bring to a boil, then reduce the heat, and simmer covered, stirring occasionally, until the sweet potatoes are soft, about 20 minutes (be careful not to overcook).

Stir in the kale and simmer just until wilted. Turn off the heat and stir in 1 tablespoon of the lime juice. Taste and add more lime juice and salt if needed.