Preheat the oven to 200°c/390°f.
Pat the rinsed beans with a clean tea towel or kitchen paper to remove any excess moisture, then spread them on the baking sheet.
Drizzle over the oil, add the salt and black pepper, and sprinkle with the garlic powder (if using).
Use a spoon or your fingers to rub the oil and seasoning over the beans, then spread them out evenly on the tray.
Place them in the oven for 20-25 minutes, until the skins are crispy and browned. Remove them from the oven and allow them to cool a little before enjoying!
