Work-week lunch is the one that wrestles me to the ground: Everything closest to my office is either loaded with fat and calories or costs at least 10 bucks. Or both. But if you don't take something, you end up so hungry, good sense flies right out of the office-tower window.
My game plan lately: A big batch of pasta salad. I can throw it together in advance, using lots of vegetables. My go-to pasta for salad is farfelle (butterflies), but penne would work just as well. To avoid mayonnaise, I use prepared pesto (or homemade, depending on how well-stocked my freezer is) loosened up with a little more olive oil. I always use roasted red pepper from a jar, chopped olives, diced onion and/or celery, and a nice handful of frozen peas.
Then, I keep around a few handy sources of protein that I can add every morning when I'm packing it up to go. Adding those at the last minute has a couple of advantages: The pasta salad part keeps longer without having to worry about cheese getting too soft or meats getting too old too quickly. And I can change it up every morning so it doesn't taste like the same lunch every day.
One day, it gets little fresh mozzarella balls cut into pieces. Another day, it gets a pouch of tuna stirred in at lunch. Or a handful of chopped salami, or a half cup of shredded deli ham, or cold cooked chicken. If I've got tomatoes, I usually add those that morning, too, so they don't get too soggy.
Make a batch on Sunday night and I've got a lunch that will get me through until Wednesday or Thursday. That saves enough time and money that I can splurge a little Friday.