Roughly dice the chicken breast lengthways and set aside. Finely dice the onions and peppers and set them aside. Heat the olive oil in a large frying pan set over medium heat. Add the onions, pepper, and bay leaf and saute until soft, about 5-8 minutes. If they’re starting to burn, lower the heat.
Mince the garlic and add to the pan. Add in the tomato paste and ⅓ cup water and stir to combine. Add the oregano, cumin, paprika, red pepper flakes, cayenne pepper powder, sea salt, and a good grind of black pepper and stir through. Add the chicken to the pan and coat with all the spices and peppers.
Pan-fry the chicken until it has cooked through. Remove from the heat. Transfer the chicken mixture to a large bowl and use 2 forks to shred the chicken. Set it aside.
In a clean non-stick frying pan set over medium-high heat, evenly sprinkle 1/3 cup of the mozzarella cheese per serving. Melt the cheese for 2-3 minutes. As the cheese melts, use a rubber spatula to gather the edges so you have a neat and round “tortilla”. When the edges begin to turn golden, slide the spatula underneath and transfer it to a plate. Repeat with the remaining cheese. Remove from heat and let cool for a couple of minutes.
Finely chop the lettuce and roughly chop the cilantro. Fill the tortilla with a thin layer of lettuce, shredded chicken, and cilantro. Serve immediately.