Preheat the grill to medium and grill the peppers, cut side down, in a heatproof dish until the skins are blackened and blistered all over. Remove from the heat and place the peppers in a bowl and cover with cling film and leave to cool.
Rub the chicken with salt, to taste and the paprika. Heat the oil in a frying pan over a medium heat and fry the chicken until golden on all sides.
Spoon about 2 tablespoons of the fat from the frying pan you browned the chicken in, into a large saucepan and fry the onion and garlic in it until soft. Add the cubetti di pancetta and fry for a few more minutes. Add the chopped tomatoes to the saucepan along with the chilli powder. Cook on high for 3 to 4 minutes and allow the sauce to reduce.
Peel the skins off the peppers and discard the seeds and stalks. Put the peppers in a blender or food processor along with any juice in the bowl. Process and then add the pureed peppers to the saucepan with the onions, garlic and pancetta. Stir to combine and heat through.
Add the chicken pieces to the saucepan, bedding them down in the sauce. Simmer, uncovered for 15 minutes, or until the chicken is no longer pink in the centre. Check the seasoning and adjust if necessary. Serve hot.
I served with boiled new potatoes but you could have rice, a salad or some nice bread to mop up the juices.