Preheat your oven to 400°F (200°C).
Wash the sweet potato thoroughly, then pierce it with a fork. Place it on a baking tray and roast in the oven for about 25-30 minutes, or until tender.
While the sweet potato roasts, steam or blanch the green beans for 4-5 minutes until they become bright green and slightly tender. Alternatively, you can toss them with a little olive oil, salt, and pepper and roast them for 10-12 minutes in the oven.
Season the lean ground beef with garlic powder, salt, and black pepper. Heat a non-stick skillet over medium-high heat and add the beef. Cook until the beef is browned and cooked through, breaking it apart with a spatula, about 6-8 minutes.
Once the sweet potato is done, remove it from the oven and let it cool slightly. Cut it into bite-sized cubes.
In a bowl, combine the cooked ground beef, roasted sweet potato cubes, and green beans. Drizzle with the remaining olive oil if desired, and toss gently to mix all flavors together.
Serve warm and enjoy a balanced, savory meal that perfectly aligns with your nutritional goals.