my go tos for meal prep dishes when i won't have time to cook and make fresh food are spaghetti, chili, chicken/rice, pulled pork, hard boiled eggs, tacos, and home made soups. easy things to divide/freeze and reheat when need a fast meal.

spaghetti: sauce in individual frozen bags can be placed in tub aware container of precooked noodles and will help keep everything cooled as it thaws until ready to reheat and eat
pulled pork and chili: very easy to freeze and simply reheat when want to eat, and not much added effort when making small portion or large portion
chicken: usually simple and freezes easy and easy to combine with other things to add variety
eggs... simply because easy and no effort
tacos: easy to adjust for variety and not much difference in making small amount vs large amount for left overs
soups: home made usually always beats store bought and once frozen very easy to keep and reheat on the go

90%+ lean turkey meatballs or Chicken breast
Steak
Salmon (I like cured because quick and easy process and I like salty stuff)
Brown Rice with steamed broccoli or any way asparagus
Salad (no dressing, just oil,salt/pepper, lemon juice) (Choice of greens is arugula, choice of cheese is feta or none, tomatos, olives, dried cranberries/raisins, nuts, flax seeds,etc. )
All sorts of fruits

JP, I can send you a 8 week meal plan. Has breakdown of all calories/fats/carbs, etc

Can PM me on Discord

I don't work so I don't need to prepare lunches. But I do still occasionally cook meals for myself. I bought some pre-marinated frozen chicken breast from walmart, and then made plain steamed rice to go with it. I imagine I could put this into a lunch box and it would be my lunch. Your lunch doesn't have to be different from your dinner.