Cook the eggs to firm hard-boiled: Place eggs in a pot of cold water, bring to a rolling boil, then continue boiling for exactly 10 minutes. Transfer immediately to ice-cold water and let sit for 3 minutes — this temperature shock makes peeling completely effortless. Peel the shells carefully, then make 3-4 shallow slits on the surface of each egg, cutting about ⅓ of the way into the egg white. The slits let the marinade seep in fully without breaking the yolk
Marinate for deep, even flavor: Put the peeled eggs in a bowl, add light soy sauce, dark soy sauce and oyster sauce. Toss gently to coat every egg evenly, then let marinate at room temperature for 10 minutes. Flip the eggs halfway through to make sure all sides absorb the sauce
First roast to set the surface: Arrange the marinated eggs in a foil-lined air fryer basket or foil pan. Spray a light, even layer of cooking oil over the top — this helps the exterior crisp up slightly and develop a deeper, richer color. Air fry at 180°C (356°F) for 5 minutes
Season and finish roasting: Pull out the basket, sprinkle barbecue seasoning generously over all sides of the eggs. Return to the air fryer and cook for another 5 minutes, until the surface looks slightly caramelized and gives off a fragrant, savory aroma
Garnish and serve: Transfer eggs to a plate, sprinkle with chopped green onions, and serve warm. They work perfectly as a standalone snack, a quick side dish, or even a protein-packed add-on to noodle bowls and rice bowls