1. Preheat the oven to 450ºF (230ºC).
2. Trim any tough ends off the kale sprouts and spread them over a baking sheet, or in a gratin dish (or two), in an even layer. They can be touching as they’ll shrink when roasted.
3. Drizzle the olive oil over the sprouts and season lightly with salt and pepper. Roast the kale sprouts in the oven on the lower third of the oven, turning them over on the baking sheet midway during baking, until they are cooked through and crisp on the outside, about 10 to 12 minutes, depending on the sprouts. (Large ones may take longer.) I like them so they are tender inside, crisp outside.
4. Remove from oven and serve warm.