Heat olive oil in a large skillet over medium heat.
Add the chopped onion and diced bell pepper; sauté until soft.
Stir in garlic; cook for about 30 seconds until fragrant.
Add the ground beef, breaking it apart with a spatula.
Season with cumin, smoked paprika, chili powder, salt, and pepper.
Add diced sweet potatoes; mix thoroughly.
Cover and cook for 15-20 minutes, stirring occasionally.
Check the doneness of sweet potatoes; they should be tender.
Remove from heat and garnish with fresh cilantro if desired.