Set up three shallow bowls: one with flour, one with the lightly beaten egg, and one with panko mixed with lemon pepper, paprika, smoked paprika, onion powder, garlic powder, Italian herbs, Dijon mustard powder, salt, and pepper. Pat the chicken thighs dry with paper towels, then place them between plastic wrap and gently pound them to an even thickness of about 3/4 inch. Season both sides generously with salt and pepper. This setup ensures a smooth, efficient coating process and helps the chicken cook evenly.

Working with one chicken thigh at a time, coat it in the flour, shaking off excess, then dip it into the egg mixture to coat both sides, and finally press it firmly into the panko mixture, making sure the breadcrumb coating adheres well to all surfaces. I like to press the panko gently into the chicken rather than just dredging it—this creates a thicker, crunchier crust that stays attached during cooking. Place each breaded thigh on a clean plate and let it rest for 5 minutes before cooking, which helps the coating set.

Preheat your air fryer to 390°F for 3 minutes. Lightly oil the air fryer basket and the breaded chicken thighs on both sides. Arrange the chicken in a single layer in the basket and air fry for 8 minutes. Flip the thighs, lightly oil the cooked side, and continue cooking for 7 to 12 minutes more, depending on thickness, until the internal temperature reaches 165°F and the coating is golden brown and crispy. The oil helps develop that satisfying crunch while keeping the chicken moist inside.

While the chicken finishes cooking, toast the brioche buns until they're golden and slightly crispy on the inside—this provides structural integrity so they won't get soggy from the mayonnaise and other toppings. Spread 1 tablespoon of mayonnaise on the bottom half of each bun and 1 tablespoon on the top half.

Place one hot chicken thigh on the mayonnaise-coated bottom half of each brioche bun. Top each piece of chicken with a handful of mixed salad greens and about 1 tablespoon of finely chopped sundried tomatoes. Arrange avocado slices (about 1/4 of the whole avocado per burger) on top of the tomatoes, then crown each burger with the top bun. Serve immediately while the chicken is still warm and crispy.