Preheat the air fryer: Set to 380°F (193°C). This helps the tortillas crisp quickly.
Prep the filling: In a bowl, combine the chicken or beef with cheese, taco seasoning, minced onion, and salsa. If using beans or green chiles, fold them in now. The mixture should be moist but not wet.
Warm the tortillas: Corn tortillas crack if cold. Wrap 6–8 in a damp paper towel and microwave 30–45 seconds until pliable. Keep them covered as you work.
Fill and roll: Lay a tortilla flat. Add 2–3 tablespoons of filling along one edge in a thin line. Roll tightly into a cigar shape. Place seam side down. Repeat with remaining tortillas.
Lightly oil: Brush or spray each taquito with a thin coat of oil. This is key for a golden, blistered finish. Do not drench—a light coating is enough.
Arrange in the basket: Place taquitos seam side down in a single layer with space between. Do not overcrowd. Cook in batches if needed.
Air fry: Cook for 7–9 minutes, flipping halfway, until crisp and lightly browned. Flour tortillas may cook slightly faster; corn may need the full time.
Check doneness: The edges should be crisp, and the cheese melted. If they need more color, add 1–2 minutes.
Serve: Let cool 2 minutes (they’re hot!), then top or dip with salsa, guac, sour cream, and a squeeze of lime.