Like Samantha26, I often take dinner leftovers to work as we have access to a microwave. My other go-to option (which I have cold) is couscous salad. You can put anything you like in it, but I usually add a combination of some of the following: chickpeas, cherry tomatoes, spring onions, sliced pickled chillies, pickled onions, cucumber, grated carrot, green lentils, celery. I keep a bottle of Kraft fat-free dressing (syn-free) in the fridge at work and add that sometimes. You can also grate cheese into it as a Hex A.