Heat oil in a large saucepan over medium/high heat. Add the chicken thighs, skin side down, and brown on both sides. Remove thighs once the skin is golden and crispy (around 10 mins). Leave the chicken juices in the pan.
Add the onion to the same pan and use the chicken juices to saute the onions over low heat, until translucent and softened. (Around 6-8 mins)
Add the garlic and cook for a further minute. Add the capsicum (bell peppers), smoked paprika and cumin and continue to cook for a further minute, adding a splash of chicken stock if the spices begin to stick.
Add the chopped tomatoes, tomato puree (paste), chicken stock and chickpeas. Stir and bring to the boil. Add the chicken thighs back into the pan, cover and simmer for 30 mins, stirring occasionally.
Uncover and remove the chicken thighs. Allow the sauce to continue to simmer, uncovered, as you prepare the chicken.
Remove the skin from the thighs and cut the meat from the bone. Shred the meat and return it to the pan. Continue to simmer until the chicken has heated through and the sauce has reduced and thickened.
Add the sour cream and chopped coriander, stir through and serve.