Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup and to prevent sticking.
Take the chicken breasts and place them between two sheets of plastic wrap. Using a meat mallet or rolling pin, gently pound the chicken to an even thickness of about ½ inch.
In one mixing bowl, combine the all-purpose flour, salt, and 1 teaspoon of taco seasoning. In another bowl, whisk together the egg, mayonnaise, and Dijon mustard until smooth. In a third bowl, mix the panko breadcrumbs with the remaining taco seasoning.
Dip each chicken breast first into the flour mixture, shaking off any excess. Next, coat it in the egg mixture, allowing any excess to drip off, and finally, press it into the seasoned panko breadcrumbs until well coated.
Place the breaded chicken breasts on the prepared baking sheet. Lightly spray the tops with oil spray to help achieve that golden-brown finish. Bake in the preheated oven for 20-25 minutes, or until the chicken is cooked through and the breadcrumbs are crispy.
While the chicken is baking, prepare your toppings. Dice the avocado and season it with a pinch of salt. In a bowl, mix the kidney beans or black beans with the chopped red bell pepper, tomato, and red onion.
Once the schnitzel is done, remove it from the oven and allow it to rest for a couple of minutes. Top each piece with the bean mixture, sliced avocado, and a generous sprinkle of shredded cheese. Garnish with fresh cilantro.
