Preheat your oven to 400°F (200°C).
Prepare the sweet potato and Brussels sprouts for roasting.
Spread the vegetables on a baking sheet and roast for 25-30 minutes.
While the vegetables roast, prepare the spinach and other ingredients.
Once roasted, remove the vegetables from the oven and let them cool slightly.
In a large bowl, combine the spinach, roasted vegetables, red onion, and walnuts.
In a small bowl, whisk together the olive oil, balsamic vinegar, salt, and pepper to create the dressing.
Drizzle the dressing over the salad and toss gently to combine.
Top with crumbled feta cheese if desired, and serve immediately.
