Heat 1 tablespoon of the oil in a large flameproof casserole dish. Add the sausages and brown all over for about 5 minutes, then remove to a plate.
Heat the remaining oil in the casserole and fry the onion, celery, garlic and peppers for 5–8 minutes, or until softened.
Stir in the chipotle or harissa paste and tomato purée, alongside the tomatoes (or passata), stock and oregano. Bring to a simmer and add the browned sausages. Season with salt and pepper and cook for 15–20 minutes more, or until the sausages are cooked through and the sauce thickened.
Add the mixed beans and stir well, then cook for a further 5 minutes.
Taste for seasoning, then sprinkle over the chopped parsley and serve with rice and salad.
