Heat a dash of oil in a large saucepan, and add the onion, garlic, carrot, pepper and mushrooms. Cook over a medium heat for 5-10 minutes, stirring regularly, until the vegetables are mostly soft (the carrots will still have some crunch to them).
Add the two kinds of beans and the tin of chopped tomatoes, along with the hot sauce and spices. Mix well, and bring to a simmer. Allow to cook for another 5-10 minutes, until the mixture has thickened and reached your desired consistency (you can add a dash of water back in if it's thickened too much).
Add the chopped parsley and plenty of salt and pepper, and transfer the bean stew to a suitable casserole dish.
Add the sliced potatoes in a single layer on top of the bean stew. Drizzle lightly with olive oil, and sprinkle with a little grated cheese.
Cover the dish with a lid or some silver foil, and bake for 30 minutes at 190°C (Gas Mark 5 / 375°F). Then remove the cover, and return to the oven for a further 30 minutes, or until the potatoes are soft, and have become golden brown and crispy.