On a cutting board, place the chicken, two pieces at a time in a gallon size plastic bag and pound with a meat mallet until about 1 inch thick.
Place the chicken, onion, and bell pepper in a bowl.
Add everything else except the flour tortillas and toppings. Mix, cover, and refrigerate for half an hour or more.
Preheat oven to 400 degrees.
Place marinated chicken mixture on a parchment paper lined sheet.
Bake for about 1 hour or until internal temperature reaches 165°F.
Remove from the oven and let it rest for about 10 minutes and then slice it with a sharp knife.
Serve the chicken and veggies in a flour tortilla with your favorite toppings.