In a hot pan, add avocado oil and fry the onion. Once golden, add the fish and the tomato. Season with salt and pepper to taste, add the cilantro. Once soft, use a spatula to shred the fish.
Heat the tortillas, fill with the fish and cheese. Secure with a toothpick, store in an oven-safe container, and let cool so they set in shape.
On the Instant Vortex control panel, press Air Fry, set time to 10 Minutes and temperature to 375°F (190°C). Press Start.
When Add Food appears on the display, remove the basket, spray the quesadillas with avocado oil, and arrange them. Put the basket back in the Instant Vortex.