Lunches are usually last night'a leftovers!
But DH polished off my prawn curry so today it's a salad - spinach, tomatoes, gherkins, kimchi, all negligible cals, with 100g cottage cheese (100 cals) and a sprinkle of mixed seeds (60 cals) for protein.
I keep a selection of salad add-ins - anchovies, artichokes, olives, capers etc in the fridge, and use feta, boiled egg, tuna for protein.
I also have a stash of soups in the office - miso, Ainsley's hot'n'sout, heinz mushroom cupasoup, and a tin of veg (whole tin is 150 cals).