Preheat the air fryer to 400°F (200°C) for 3–5 minutes.
A hot basket helps create crisp edges.
Trim and cut the pork. Remove any silver skin from the tenderloin. Cut into 1- to 1.5-inch cubes for even cooking.
Season generously.
In a bowl, toss pork with 1–2 tablespoons oil, 1 teaspoon kosher salt, 1/2 teaspoon black pepper, 1 teaspoon garlic powder, 1/2 teaspoon onion powder, 1 teaspoon smoked paprika, 1/2 teaspoon dried oregano, a pinch of red pepper flakes, and 1 teaspoon brown sugar if using.
Rest the seasoning for 5 minutes. This lets the salt draw in and helps the spices cling.
Arrange in the basket in a single layer with space between pieces. Work in batches if needed.
Crowding leads to steaming, not browning.
Air fry for 8–10 minutes, shaking or flipping halfway. Start checking at 7 minutes. You want browned edges and a juicy center.
Check doneness.
Pull at an internal temperature of 145°F (63°C). The carryover heat will finish the job while the bites rest.
Rest 3–5 minutes. This keeps the meat juicy.
Squeeze with a little lemon and sprinkle with herbs before serving.
Serve with your favorite sides: roasted veggies, rice, mashed potatoes, or a crisp salad. They’re also great with garlic yogurt sauce, barbecue sauce, or honey mustard.