Heat a dash of oil in a saucepan, and add the onion. Cook for a few minutes over a medium heat, stirring regularly, until the onion is soft and translucent. Add the mushrooms and garlic, and cook for a further 5-10 minutes, until soft.

Add the tin of black beans, the spices, and the crumbled stock cube. There should be a bit of moisture in the pan from the mushrooms, but you can add a tablespoon or two of water if needed. Allow to cook, stirring occasionally, for at least 5 minutes, until the mixture looks thicker and richer.

Add the diced tomatoes, and season to taste. You can also add some extra spice if needed. Cook for a few more minutes, until the tomatoes have softened.

Serve with your choice or sides and toppings - I used rice, sour cream, grated cheese, and chopped coriander (cilantro).