Preheat your air fryer. Set it to 380°F (193°C) for 3–5 minutes. A hot basket helps with immediate browning.
Slice the potatoes. Cut into 1/4-inch thick half-moons or small wedges.
Keep the size consistent so everything cooks evenly.
Slice the onion. Halve it root to tip, then slice into 1/4-inch strips. Too thin and they’ll burn; too thick and they won’t soften in time.
Season in a bowl. Toss potatoes and onions with oil, salt, pepper, garlic powder, paprika, and thyme. Everything should look lightly coated, not greasy.
Load the basket. Spread in a mostly even layer.
A little overlap is fine, but don’t overload—cook in two batches if needed for maximum crispiness.
Air fry for 10 minutes. Shake the basket or stir halfway through to prevent sticking and promote even browning.
Stir and continue. Air fry for another 8–12 minutes, shaking every 4–5 minutes, until potatoes are golden and tender and onions are caramelized at the edges.
Finish and taste. Sprinkle with fresh herbs and a small splash of vinegar or lemon juice. Adjust salt and pepper to taste.
Serve hot. They’re best right away, while the edges are crisp.