- Preheat the oven to 425 degrees Fahrenheit.
- On a large, rimmed baking sheet, combine the prepared potatoes, bell pepper and onion. Drizzle the olive oil over the vegetables, then sprinkle the garlic powder, salt, and several twists of freshly ground black pepper over them. Toss until they are evenly coated in olive oil, and no powdery spots from the garlic powder remain. Arrange them in an even layer on the sheet.
- Bake until the vegetables are tender and deeply golden on the edges, about 45 to 50 minutes, stirring every 15 minutes for even browning. (The potatoes like to stick to the pan, so I find that using a metal spatula with a sharp edge helps me get underneath them without breaking off their crispy parts.) Serve immediately.