meal-planning and meal-prep are the main ways. Even if you have the ability to “cook” it at the office, you still need to do both of those things. I would roast some veggies, roast some sweet potatoes, cook some rice or other grain, maybe cook a couple chicken breasts, and then portion those into “bowls” maybe with some kind of dressing for flavor. Pop that in the microwave at the office and there you go.