I make this all the time. Cinnamon and honey are my favorties and I'm addicted to sweet/savory combinations. I prefer the red onion but any onion will do. It's especially yummy if you let the onions and edges of the sweet potatoes get a little brown and crispy.
Sweet potatoes, diced
Red or white onion
Olive oil, any flavor
Salt and pepper
Place sweet potatoes and onion in a baking pan. Drizzle over honey and olive oil. Sprinkle with cinnamon, salt and pepper and mix to coat. Bake at 375 degrees until potatoes are tender. About 40- 45 minutes.