I've only been doing this for a few weeks, so I don't have a ton of ideas yet, but on the weekend I roasted 8 chicken thighs.
A couple of days this week I made a big ass salad of mixed greens, shredded cabbage, baby cucumber, orange pepper, balsamic vinegar/olive oil dressing and two shredded chicken thighs on top.
I've done other versions of this salad with tomato and feta cheese instead of the chicken.
Hard boiled eggs transport well, as does cold cooked bacon
Dinner leftovers work well too. Tomorrow's lunch will consist of some cold pork tenderloin and sweet potato/white potato mash (with butter!).