Peel the sweet potato and dice it into small 1/2-inch cubes to ensure even cooking.
Heat the olive oil in a large cast-iron skillet over medium heat.
Add the sweet potato cubes to the skillet and cook for 8-10 minutes, stirring occasionally, until they begin to soften and develop a golden-brown crust.
Stir in the diced yellow onion and red bell pepper, cooking for another 3 minutes until the onion becomes translucent.
Add the ground beef to the skillet, breaking it up with a spatula, and cook until the meat is fully browned and cooked through.
Sprinkle the garlic powder, sea salt, black pepper, and smoked paprika over the beef and vegetable mixture, stirring well to coat everything evenly.
Fold in the chopped kale and cook for 1-2 minutes until the leaves are just wilted and bright green.
Remove from heat and serve immediately while hot.