Preheat the air fryer. Set it to 390°F (200°C). A hot basket helps the potatoes crisp faster.
Prep the potatoes. Rinse and dry the potatoes well.
Halve baby potatoes; quarter larger ones so all pieces are similar in size.
Make the seasoning mix. In a large bowl, whisk olive oil, melted butter, Dijon, salt, pepper, garlic powder, onion powder, thyme, and smoked paprika.
Toss to coat. Add the potatoes to the bowl and mix until every piece is glossy and evenly seasoned. Don’t skimp here—coating matters for crispness.
Load the basket. Place the potatoes in a single layer. Slight overlap is fine, but avoid piling.
Work in batches if needed.
Air fry, then shake. Cook for 10 minutes, then shake the basket or turn potatoes with tongs. This helps even browning.
Finish cooking. Air fry for another 8–12 minutes, until the edges are deep golden and the centers are tender. Total time is usually 18–22 minutes.
Taste and adjust. Sprinkle a pinch more salt if needed.
Toss with parsley and lemon zest right before serving for a fresh lift.
Serve hot. Pair with roasted chicken, grilled steak, pan-seared salmon, or a creamy dipping sauce like garlic aioli.