Heat the oil in a large pan. Cook the chorizo, onion and chicken over a high heat for 5 mins. Add the tomato and cook for a further 2-3 mins until pulpy.
Stir in the beans, potato and stock. Bring to the boil, then cover and gently simmer for 20 mins until the potato is soft and the chicken cooked through. Stir through the parsley and serve. You can cool and freeze the stew for up to 2 months. To serve, defrost and heat through thoroughly.