Tear kale leaves away from tough center stems; discard stems. Cut kale into 2-inch pieces and place in a large bowl. Add oil and sprinkle lightly with salt and pepper; mix well to coat. Spoon into a 9- by 13-inch baking dish (kale will fill dish).
Bake in a 450° regular or convection oven, stirring occasionally, until top pieces of kale are crisp and remaining are tender to bite, 20 to 25 minutes. Stir in preserved lemons or lemon peel and spoon into a bowl. Serve hot or at room temperature.