For work I would either take in salads made with cos lettuce, cucumber, peppers, sweetcorn,radishes, sunflower and pumpkin seeds, beetroot and for protein I would add either tinned tuna, poached salmon, boiled chicken, prawns or cheese. I drizzle over balsamic too.
Or I would take in the little pots of low-fat houmous with carrot sticks, pepper sticks and raw baby corn
Or M&S have some fabby tiny portions of BBQ chicken pieces/Prawns/chicken satay that you can eat cold and they are full of protein.