Even though I had access to a fridge and microwave when teaching, I usually didn't bother. I've always cooked big batches of one-dish meals & divided them into single servings each with my protein/vegs for 1 meal, then froze them. Also cooked chicken, roast beef, fish etc. & stored single servings in the freezer. I'd take a salad + frozen protein or a frozen one-dish meal to work & it'd be thawed by lunchtime. They also served as dinners when I came home late & didn't feel like cooking, just reheating something yummy & nourishing. I'm retired and still do this. There is no excuse to eat crap when you've always got a variety of ~20 meals ready to go.