I wouldn't do this with the pasta and sauce - it comes out slimey as anything and really unappetising. I have had more success making it in a flask 10-15 mins before you want it but you need to add less water.
There are numerous threads on here with people looking for lunch ideas so I would take a look at them. Your position is really no different to someone looking for lunches to have at work, although they be lucky and have more facilities on hand.
You can invest in a food flask and take curry, chilli, stews, soups etc although these ttend to work better with things that come in a sauce.
There are numerous variations on pasta, rice and cous cous salads that are really easy to make up the night before and pack out with loads of veggies. Having pasta for dinner? Then make a bit more for the following day's lunch.
Again lots of variation on the SW quiche to fit with whatever plan you are following and your tastes. For a more classic version you could try frittata instead.
Just about any soup can be made SW friendly so there are lots of possibilities there - you can even make them more filling just by adding rice, pulses, broken up spaghetti or mini pasta shapes.
As said you could ask or take hot water to make up a mugshot, or the Ainsley Harriott cous cous work well like this. Just empty the sachet in to a tupperware type box with the water. Pop on the lid and its ready in 5 mins. Throw in some baby tomatoes and you're good to go!
Then there are sandwiches, rolls or crispbreads with your own home-made filling.
Don't feel awkward about self-catering - just tell your friends that you are trying to save a bit of money, and soon enough they will be jealous of all the lovely grub you are having while they are still on the nasty pizza!
A few links that may also be useful
Lunchbox recipes - Recipes - BBC Good Food
Cheap Healthy Lunch Ideas for Work | Eating Well
Lunch Recipes and Menus - On the Run Lunch Recipes - Brown Bag Lunch Recipes