I pack it in tupperware (my wife gets glass) and it all goes in the pannier with a thermos of coffee. I do not chill it, microbes come and get me...
I leave a full set of dishes, cutlery, a few mugs, hand towel and napkin at work. I have a place to wash and store the dishes and the towel is used for fruit transport and get home every two or three days and the napkin once or twice a week for a wash.
I rarely heat up my food but I almost always serve it on a plate or in a bowl. I used to have a tea pot and french press but they got lost in my two year work hiatus. Now I just use tea bags and a drip filter. I have been thinking of a Soda Stram for my bubbly water fix at work, but that may be much.
I usually pack a huge salad jammed in a cube 1L tupperware. I put all my cut veggies in the tupperware first and then layer the lettuce and spinach on top, then the greens are not crushed and soggy. I then turn it out on a plate and mix the veggies and pour over my dressing. If I bring egg or cheese I pack it separate.