Remove the seeds and stems from the bell peppers and chilli peppers,then chop up roughly. Place all peppers on a tray and grill for 5-10 mins until skins start to blacken. check and turn regularly.
Place the charred peppers in a blender along with the rest of the sauce ingredients and blitz into a smooth paste. Taste and add more Tabasco or yogurt if required.
Next prepare the chicken by scoring 3 lines, about half a cm deep, in the top of each breast. This will allow the marinade to infuse with the meat.
Take a wide oven proof dish and line with foil. Spoon ⅓ of the chipotle sauce into the base of the dish and spread evenly over the foil. Then place the chicken, slit side down, on top of the sauce. Spoon another ⅓ of the sauce over the chicken and spread evenly over the meat.
Place the remaining third of the sauce to one side. Cover the oven proof dish with foil and place in the oven for 40 minutes.
After 40 minutes check the chicken and pour off any juices, then recover and return to the oven for another 10 minutes.
Next remove the chicken and use a sharp knife and fork to shred each breast, allowing the chunks to mix with the sauce. Then recover and return to the oven for a final 10 minutes.
Whilst the chicken is its final stages of cooking prepare the rice and lay out all the other fillings ready to load into the burritos. Once the chicken is ready heat the wraps for 10-20 seconds in the microwave and lay out ready to fill.
Place the fillings on the wraps in rows, with the first row starting about inch in from the side of the wrap closest to you. Leave an inch of wrap either side of the row - do not fill to the edge.
Follow the first row of chicken with rice, then sliced avocado. This can then be topped off with some of the chipotle sauce left over from earlier, any remaining yogurt and chopped parsley.
To wrap the burritos, take the edge nearest to you over the fillings and at the same time fold in either side of the wrap and took under the first fold. continue to roll over and secure the wrap by placing a small blob of yogurt on the inner edge.
Slice in half if desired and serve with any remaining chipotle sauce, yogurt and chilli