First step is to prepare the leek, onion, garlic, chorizo and potatoes. Peel and cut potatoes into quarters and leave in some water, then chop the onion, leek, garlic and chorizo into slices and leave to the side. Using a casserole dish fill with about a centimetre of oil and heat. Once the oil is heated add the chicken thighs and cook for about 6 mins turning them in between. Remove the chicken thighs and keep to the side for later. Now add the onion, leek, garlic and chorizo slices (you may want to crush the garlic slices with a spoon to release flavour) and cook until the contents is slightly browned meanwhile use this time to boil some water, add the stock cubes to a measuring jug and fill to 600ml with water. Once browned add the tin off chopped tomatoes and stock to the casserole dish, now add the potatoes and chicken thighs to the dish and cook for 20 mins. After twenty minutes wash and add the tin of red kidney beans and cook for a further 20 mins then serve.