Heat the olive oil in a large pot over medium heat. Add the ground beef and cook until browned, breaking it up with a spoon as it cooks.
Add the diced onion and minced garlic to the pot. Stir and cook for 3 minutes until the onion softens.
Stir in the diced sweet potatoes, diced tomatoes with their juice, beef broth, thyme, paprika, salt, and black pepper. Bring the mixture to a boil.
Reduce the heat to low, cover the pot, and simmer for 15 minutes until the sweet potatoes are tender.
Add the chopped kale and stir it into the stew. Simmer uncovered for 5 more minutes until the kale wilts.