1
Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry produce.
Cut potatoes into ½-inch-thick wedges. Halve, peel, and grate ¼ of the onion (half for 4) on the largest holes of a box grater; cut remaining into ½-inch-thick wedges. Halve, core, and thinly slice bell pepper into ½-inch-thick strips.