After having a tiny bit of trouble finding this place, I eventually walked into a 1900's food store. There are people walking around in white coats and funny cinema type seats. Definitely a caferteria feel about it, but not in a horrible way. On one wall there are hundreds of sauces, preserves, pickles and jellies. I ordered my beef sandwich and vegetable soup from the counter. The beef sandwich was delicious - 10 out of 10. The soup was very good but I've had better - I'd give it 7/10.
A lovely sandwich shop that's worth a visit - especially to avoid Subway and Pret.