Peel and dice the sweet potato into small 1/2-inch cubes to ensure even and quick cooking.
Heat the avocado oil in a large cast-iron skillet over medium heat.
Add the sweet potato cubes to the skillet, covering with a lid for 5-7 minutes until tender, stirring occasionally to prevent sticking.
Remove the lid, add the diced yellow onion and red bell pepper, and sauté until the vegetables are softened and slightly browned.
Push the vegetables to the outer edges of the pan and add the ground beef to the center, breaking it up with a spatula.
Season the entire skillet with garlic powder, smoked paprika, sea salt, and black pepper.
Cook until the beef is fully browned and no pink remains, then stir everything together to combine the flavors.
Add the chopped kale and stir for 1-2 minutes until the leaves are just wilted and bright green.
Serve immediately while hot, straight from the skillet.