>I'll cook something ahead of time at home if it reheats well.
OP, just fill up a 9x12 baking dish with seasonal choices of mixed veggies, tossed in olive oil, sea salt and pepper. Enjoy various combinations. Seasonally, you could enjoy winter squash like acorn or butternut in nice chunks, some big chunks of onion, bell pepper, toss in some parsnips, carrot, sweet potato, whatever. I'd like to suggest combinations, but honestly, just try to handle the size ratio so that they are all caramelized at the same time.
If you're grilling some dinner on your gas grill (or broiling your dinner, like a flank steak), it's not much more work to lay out some thick slabs of zucchini, peppers, eggplant, vidalia, portobello, basted in a bit of olive oil, balsamic, rosemary, or maybe some chili-lime. When chilled down as leftovers, it's a yummy work lunch. Pair with other leftovers, from some rice to sliced steak. Toss with more dressing. Or steam a brown rice 5 mins at the work microwave.
Cold, previously steamed,edamame is a wonderful snack. As are most cold bean salads, that you can prepare over the weekend. Soak and cook very nice local produce like speckled butter beans, purple hull peas, black beans, hit them with salsa fixins: lime, tomato, onion, peppers, cilantro. Chill, and enjoy with some cassava chips or plantain chips. You could start with canned, but they have a different texture overall. Texas caviar, google the recipe. Do the 5bean salad sweet and sour flavors too, if you like, but make it fresh. Potato salads are crazy good at work, basically nuke a potato, cube it, hit it with all your veggie and meat leftovers and dressing, chill overnight.