Preheat your oven to 400°F.
Wash the sweet potato well, then cut it into cubes or wedges. Toss with a teaspoon of olive oil, a pinch of salt, and pepper.
Place the sweet potatoes on a baking sheet and drizzle a bit more olive oil if desired. Roast in the oven for about 25-30 minutes until tender and slightly caramelized.
While the sweet potatoes roast, season the beef sirloin with salt, pepper, and finely chopped rosemary.
Heat a grill pan or skillet over medium-high heat. Sear the beef sirloin for about 3-4 minutes on each side for a medium-rare finish (adjust cooking time based on thickness and your preferred doneness).
In the final 5-7 minutes of the sweet potatoes’ roasting time, add the green beans (tossed lightly with a splash of oil, salt, and pepper) to the baking sheet. Roast until the green beans are tender-crisp.
Once everything is cooked, let the beef rest for a few minutes before slicing.
Plate the sliced beef sirloin with a serving of roasted sweet potatoes and green beans. Enjoy your balanced, nutrient-rich meal!