Preheat oven to 400 degrees. Chop kale finely. Chop the onion.
Combine kale, carrots, onion, garlic and olive oil in a large bowl and use your hands to mix it well. Make sure all the kale gets massaged with oil.
Spread in a 13 x 9 baking dish and cook 20-25 minutes, stirring once halfway through. (The carrots should be tender and the kale wilted and brown in spots.) Sprinkle lightly with salt and parmesan if using, and enjoy.