1. On a large baking sheet toss the sweet potato cubes with a little olive oil and salt and pepper. Roast the sweet potato cubes in a 400 F oven. Make sure you turn the sweet potatoes a couple of times while they are roasting. Roast until soft, about 30-40 minutes. Remove from oven and set aside. Prepare salad.
2. Place the fresh spinach on a plate. Add the roasted sweet potatoes, apple slices, red onion slices, and feta cheese. Drizzle with balsamic dressing. Enjoy!