Cook the kidney beans in plenty of water until very tender, remembering to rapid-boil them for ten minutes at some time during cooking. Drain the beans, reserving 2 cups of cooking liquid. If using chickpeas, cook them separately (no need to rapid-boil).
Meanwhile, bake the pepper(s) whole until soft and the skin begins to char. Allow to cool, then remove and discard the skin, seeds and membranes. Roughly chop. Peel and gently boil the potatoes until tender, then mash with salt, pepper, rice milk and margarine - enough to make a creamy mash.
Dice and slowly fry the onion in a splash of oil over medium-low heat until nicely browned. Add the pepper and sprinkle over the flour. Stir to coat evenly, then pour in the bean broth and seasonings. Bring to the boil, then reduce heat and simmer, stirring frequently until thickened. Add the cooked and drained beans/chickpeas. Taste and adjust seasoning if necessary.
Put the mixture in a large casserole dish and top with the mashed potato. Bake at 180 degrees Celsius to reheat and crisp the top; about half an hour. Allow to cool for ten minutes, then serve with steamed green vegetables.
My skeptical omni aunt helped me think up the name for this dish... she said there's no such thing as a 'vegetarian shepherd's pie', like I used to call it... so vegherd's pie it became - i.e. for those who herd vegetables! :-D