Preheat oven to 220°C.
Cut off the ends of the Brussels sprouts and pull off any yellow outer leaves. Mix them in a bowl with the olive oil, salt, and pepper. Transfer them to a sheet pan and roast for 35 to 40 minutes, until crisp outside and tender inside. Shake the pan from time to time to brown the Brussels sprouts evenly. Sprinkle with more salt (I like these salty like French fries) and serve hot.