Thinly slice chicken breast into small pieces. Season with garlic powder, onion powder, salt, pepper, Tajìn and smoked paprika. Allow to marinate for at least 15 minutes
Thinly slice bell peppers in onions.
Heat a skillet over medium heat and add a drizzle of oil. Once the oil is hot, add the chicken and cook until it's almost cooked through. Next add in the peppers and onions. Sautè until your desired doneness and the chicken is cooked through.
Reduce the heat, then add the cheese. Cover and allow the lid to the pan and allow the steam to melt the cheese. Move the chicken and cheese to one side of the pan. Add a knob of butter and toast the buns.
For the sauce combine mayo, Sriracha, chili garlic sauce. Mix until combined.
Assemble the sandwich by adding a bit of the chicken + cheese mixture. Top with the sauce and enjoy!