Heat a Tbsp of olive oil in a large casserole dish. Add the chicken pieces, turn down the heat and gently brown them on each side.
Meanwhile, peel and thinly slice the onion & garlic, deseed & slice the red pepper. Measure out the spices into a small bowl, add the sugar and set aside.
When the chicken pieces are light brown, transfer them to a plate.
Add another spoonful of olive oil to the pan and add the onion and pepper. Gently sauté for about 8 minutes until soft, then add the garlic and cook for another minute.
Add the spice mixture, stir for 30 seconds, then add the chipotle paste. Stir for a few seconds, until sticky then pour in the tomatoes. Add some water then stir in the beans. Season with salt and pepper. Put the chicken pieces back, coat them well in the sauce.
Gently simmer under cover for 45-60 minutes. Alternatively put the dish (with the lid on) in a medium hot oven, and bake for 45-60 minutes.
Serve with the coriander leaves scattered all over.