Heat the olive oil in a large pot over medium heat. Add the diced onion and cook until it softens, about 5 minutes.
Stir in the garlic and ginger. Cook for 1 minute until fragrant.
Add the sweet potato cubes, vegetable broth, peanut butter, cumin, and smoked paprika. Stir until the peanut butter melts into the broth.
Bring the mixture to a simmer. Cook for 15 to 20 minutes until the sweet potatoes are tender.
Stir in the chopped kale and cook for another 5 minutes until it wilts.
Season with salt and pepper. Serve hot with a squeeze of lime juice.