My kids LOVE roasted beets. You just peel, cut into wedges, toss them with a tablespoon of olive oil, put on a baking sheet, and bake at about 425 for 20-25 minutes. You can flip halfway through, but I don't.
I did make beet salad with carmelized sweet onion the other day.
Kids gagged on it because of all the different textures, but DH and I loved it.