Preheat your oven to 180°C (350°F). Deseed and roughly chop the bell peppers and chili peppers, then spread them on a baking tray. Grill them for 5-10 minutes, turning occasionally, until the skins start to blacken. This charring step is what gives the sauce its smoky flavor, so don't rush past it.
Transfer the charred peppers to a blender along with the ginger, garlic, walnut oil, yogurt, Tabasco, and salt. Blitz until completely smooth. Taste it here and adjust more Tabasco for heat, more yogurt if it feels too fiery. You should end up with a silky, deep orange sauce.
Score three shallow lines into the top of each chicken breast so the sauce can soak in. Line an oven-proof dish with foil, spread a third of the sauce on the bottom, then place the chicken on top, scored side down. Spoon another third of the sauce over the chicken and spread evenly.
Cover the dish tightly with foil and bake for 40 minutes. Check on it, drain off any excess liquid, then re-cover and bake for another 10 minutes. The chicken should be fully cooked through and very tender by this point.
Take the chicken out and shred it right in the dish using a knife and fork, mixing it into the sauce as you go. Cover again and pop it back in the oven for a final 10 minutes so the shredded chicken really soaks up all that flavor.
While the chicken finishes, warm your tortillas for 10-20 seconds in the microwave so they're pliable. Lay the fillings in a row down the center chicken, rice, avocado slices leaving space on each side. Top with the reserved sauce, a spoon of yogurt, and chopped parsley.
Fold the edge closest to you over the filling, tuck in both sides, then roll it up tightly. Seal the edge with a small dab of yogurt to hold it closed. Slice on the diagonal if you like a fancier presentation, and serve right away.