Heat 1 tbsp oil in a large skillet over medium-high heat. Add ground beef, season with a pinch of salt and pepper, and cook until browned about 5–6 minutes. Drain excess fat if needed, then set beef aside.
In the same skillet, add the remaining oil. Sauté onions and bell peppers 4 minutes, then stir in garlic. Add diced sweet potatoes and cook 5 minutes.
Stir in oregano, thyme, smoked paprika, chili powder if using, salt, and black pepper. Add diced tomatoes and beef broth. Mix well.
Reduce heat to medium-low, cover, and simmer 15–20 minutes, stirring occasionally, until sweet potatoes are tender.
Return beef to skillet. Stir in fresh cilantro. Taste and adjust seasonings.