Heat a large pot on a medium heat and spray well with one kcal spray.
Add the onion and cook until softened.
Add the red pepper, garlic, cumin, paprika and thyme and cook for 2-3 minutes on a low heat stirring frequently to release all the flavours from the spices.
Add the tomatoes, one tin of water and bring to a simmer.
Stir in the stock pot/cube and season with pepper.
Reduce heat to a low temperature, cover and allow to cook for at least 30 minutes (the longer you leave it, the better the flavour. You can even add it to a slow cooker and leave it cook overnight/while you are at work).
Before serving, bring the stew to a simmer and add in the raw diced chicken breasts.
Cook for a further for 5-10 minutes stirring from time to time (until the chicken is cooked and white throughout).
Serve with rice, potatoes, pasta, or crusty sourdough bread.