Do you have a freezer? Meal prep for 5 days, but freeze half into portions. Do two preps once to get some in the freezer, then just do it once a week from then on. If you do something different each time, after a few weeks you'll be able to eat something different every night.
Pick things that freeze well. I find saucier things or minced things freeze best. Lasagne, stews, pulled pork, minced beef for burritos (if you're adding rice, probably cook that on the day you eat it. I would avoid freezing rice I think.
Many Indian and westernised Indian dishes will freeze well, but I'd go for the vegetarian ones or test freezing smaller portions of dishes with hunks of meat. E.g. I find cooked chicken doesn't freeze well, it dries out.
The idea is you cook a protein, prep some veggies on meal prep day, and then throughout the week make 3 different dishes, each using the same protein and some of the prepped veggies, that each take like 20 minutes total - most of that being oven time, since all the ingredients are already cooked.
It's a good balance between cooking every night and eating chicken and broccoli 5 days a week.
It looks like they'll send a free weeks recipe if you want to try it.
Are you on a diet? You can grill tilapia ahead of time to use as protein. Eat as is or in a salad. Add some quinoa for some texture or as a side dish, green leaves, hearts of palm, tomatoes. Some pickled beets.
Don't make all your meals the same, do like taco bell: combine the basic ingredients in different ways to achieve dune variety. One day, keep the protein and gain and salad separate. The other, mix it all in a big salad bowl. Omit an ingredient. Add something else (peanuts?). Use different sauces (hot, cool, savory).
Pasta salad lasts about 2 or 3 days well, in my opinion. It's a great option one or twice but it doesn't scale well for weeklong meal prepping.
A roster of shelf stable foods to mix up a mono-diet helps immensely. Nothing that takes more than a few minutes or steps--a case of ramen, a box of cereal, and/or some frozen foods keep thing varied and palatable regardless of whatever meal prepping system works out for you. Just as backups when you just don't want another goddamned piece of parmesan-panko-chicken, and so on.
My goto in my younger less reliably incomed days was always hardboiled eggs and dried beans I'd soak overnight and slowcook with onion the next day.
Here's a suggestion for your recipe book: Chicken parts cooked for 1.5 hours in an slow cooker (browned first), covered with a mixture of two cans of mushroom soup and two packages of French Onion soup (the powdered kind.) Man, you won't be disappointed and it's easy.