We visited Crumbs yesterday whilst in Cardiff. It is a nice café that is almost completely vegetarian but not quite. They do serve tuna apparently due to public demand and them not being able to survive if they didn't! The owner did at first tell us that they were 100% vegetarian and then, when asked about the tuna, revised that to 99.9% vegetarian. That aside, it is a nice lunchtime café. We had jacket potatoes with the veg chilli and the portions were a good size. The chilli wasn't too hot which is how we like it! Unfortunately no dairy free margarine was available. For dessert we had the chocolate cake and the vanilla and cherry cake. Both of which were delicious.
Cons: Serves Tuna, No dairy free margarine