In a medium bowl, combine the ground chicken, kosher salt, garlic powder, and onion powder. Mix gently with your hands until just incorporated; do not overwork. Let rest for 5 minutes while you set up your breading station.

Lay a large sheet of parchment paper on a work surface and dust it generously with flour. Place the seasoned meat in the center and press it into a very thin, large oval, about 1/4-inch thick, aiming to nearly fill a standard half-sheet pan. Lightly dust the top of the meat with more flour.

Brush the top surface of the meat with the egg wash. Evenly sprinkle about half the panko over the egg wash, pressing gently so the crumbs adhere. Spray the panko generously with avocado oil until it looks fully hydrated and glossy—this is crucial for a crispy oven-fried texture.

Place a second sheet of parchment on top of the cutlet, then carefully flip the entire stack. Peel away the top parchment to reveal the uncoated side. Brush with remaining egg wash, cover with the rest of the panko, press gently, and spray again with avocado oil until the crumbs are fully moistened.

Lightly spray a large sheet pan with avocado oil. Transfer the cutlet from the parchment to the prepared pan. Bake in a preheated 450°F convection oven (or use the air fryer setting) for 15 minutes, until the crust is set and starting to brown.

Switch the oven to broil and cook for 4 to 5 minutes, watching carefully, until the cutlet is deeply golden brown and shatteringly crisp.

Remove from the oven and immediately sprinkle with flaky sea salt. Let rest for 1 to 2 minutes, then slice and serve.