Begin by rinsing the green beans under cold water and then patting them completely dry with a kitchen towel. This ensures they crisp nicely in the air fryer.
Place the dried green beans in a mixing bowl. Drizzle them with olive oil and toss well to evenly coat all the beans.
Add the sea salt, black pepper, and garlic powder to the bowl. Toss again until the seasonings are evenly distributed, ensuring every bean gets flavor.
Preheat your air fryer to 200°C (390°F) for about 3 minutes. While it heats, spread the seasoned green beans in a single layer in the air fryer basket, avoiding overcrowding for optimal crispness.
Roast the green beans for 8–10 minutes, shaking the basket or tossing the beans halfway through to promote even browning and crisping. You’ll hear a gentle crackle and see some charred spots starting to form.
Once cooked, remove the basket from the air fryer and transfer the beans to a serving dish. If desired, sprinkle with lemon zest or squeeze a little lemon juice over the top for a fresh, zesty contrast.
Serve immediately while the beans are crispy and aromatic. Enjoy their smoky flavor and satisfying crunch as a healthy snack or side dish.