Preheat your oven to 400°F/200°C.
Rinse the chickpeas in a small colander or through a sieve. Drain them well.
Transfer the chickpeas to a rimmed baking sheet and use tea towels or paper towels to roll them around and pat them as dry as you possibly can. The more dry the chickpeas become, the crispier they'll be. Make sure there's no extra liquid left on the baking sheet once you're done drying the beans; if you see any, use the towels to wipe it off.
Drizzle the chickpeas with the oil and use your hands or a spoon to coat them evenly. Sprinkle them with the onion salt, garlic powder, and a few turns of black pepper. Mix again.
Transfer the baking sheet to the oven. Roast the chickpeas, stirring them once halfway through cooking, until they're a deep golden brown and very crispy, 25 to 35 minutes.
Serve right away, or meal prep for the week by transferring the chickpeas to a single airtight container. Store for 3 days at room temperature (to retain more crispness) or 5 days in the fridge. Enjoy at room temperature or reheat them in a 300°F/150°C oven for about 15 minutes.