First off, don't for one second believe that any of the following suggestions that I am going to give you are going to be ideal. most of my suggestions are going to be processed food and also be higher in sugar. too bad! you are looking to make the best out of a bad situation here. if the world was perfect, we would be able to sit down and eat every meal slowly and peacefully, however that shit ain't happening here.
I am a personal trainer and I get my balls broken to no end about eating on the gym floor, even if I have 5 or 6 clients in a row which would easily violate my eat every 2 to 3 hours rule(my company doesn't seem to give a shit that I am fit, just that I sell fit and make them money I guess).
I think you have been given some very good advice here. eat the microwave meal on your 30 min break and then save all the other stuff in your desk/locker, and eat it while you can.
I take whole wheat bread and toast it in the morning and smother it with natural peanut butter and fruit preserves. Put it in the fridge in a baggie or tupperwear, and eat it when you can, it tastes fucking amazing. another option it to make a big salad and leave it in your desk drawer and pick at it while you can. protein shakes work very well, as do power bars and protein bars. raisins, beef jerky, milk and some fruit/vegetables will also suffice (pick at bags of spinach, carrots, bananas, grapes, oranges, apples if you can eat them fast, I have to hide them whenever my manager comes downstairs)
If you cannot make the above suggestions work then I suggest that you either get a new friggin job or rethink your goals and make them not all too aggressive. I have gone to the extent of having clients come in 15 minutes later just so I can eat, or not agreeing to appointments at all. Life is all about priorities and the decisions that you make on a daily basis reflect what your priorities really are. talk is cheap, action is where the money is.