In large skillet over medium heat, heat olive oil. Add onions and bell pepper; cook, stirring occasionally, until peppers are softened, 5-7 minutes. Season with salt and pepper, to taste.
Add sweet potatoes, black beans and chili powder; stir to combine. Cook until potatoes and beans are warmed through, 4-5 minutes.
Divide bean mixture between two bowls. Top each bowl with fried egg, avocado slices and crumbled cotija cheese. Serve with lime wedges.