Add the chopped tomatoes, ajwain, onion, black pepper and a drop of water to a blender and blend to a liquid.
Put the liquid and tomato puree into a pan and heat, reducing any runny liquid.
Add the mixed beans and if needed, crush with a fork to reduce the lumpy texture.
In a frying pan, add a little butter and place a wrap. Add the mixture to half.
Top the half with as much cheese as desired and fold over.
Cook each side until golden and the cheese is melted.
Cutinto manageable strips and serve.