Roasted veg with chicken or tuna
Lentils/tarka dhal with chicken or tuna
Green salads like green beans, peas, watercress, nuts, salmon/prawns/tofu
I dont put any carbs (or very few) in with it so lots of protein component
Mix it up from time to time adding in houmous and avocado. I use lots of nuts, hazlehuts, almonds, peanuts, walnuts, cashews, a whole mixture.
Cheese and grated carrot is a surprisingly nice mixture
I do a combination of all of the above so I dont get bored like you say OP!
Im not keen on soups to take to work, too sloppy and messy, too hot in the microwave and then I need to carry it to my desk - a high risk activity!!