Depends on what they're made of, I guess.
The idea of edible pasties doesn't sound too bad.

A bacon cesar salad always works and you can shake it too mix the flavours ;) and anything goes with salad.

Stupid question, but how is that packable? :P

usually in a smallish(depends on size) tupperware plastic container.

super cheap and air tight just don't dishwasher them, i had 1 change colour once.

In third world we use hands along with soaps/detergents for washing purposes.

its cheaper too cause machines breakdown, the only way i found out was i made a co worker a salad and she offered to dishwasher them and return the favour it was a interesting surprise i thought she had made a curry or something? i thought it was relevent information ;)

Simple sushi and Vietnamese spring rolls would be my personal choice, I've done that before.
You just eat them cold with some dipping sauce.

The preparation takes some time but actually making them is rather quick.
You don't have to use fish with the sushi, in practicality you can use almost any kind of meat.
There's a whole bunch of pre-made dipping sauces you can buy.

The good thing about all this is that you can vary the ingredients, so you get different flavours.
Using different sauces also adds some variety.

Other favourites:
* cured herring or some other canned or smoked fish (mackerel ... ) + some nice bread
* Noodle salad = cold noodles with peanut sauce and whatever protein, vegetable and salad you have
making peanut sauce is quick and easy, you could use a spicy sauce as well
* pre-made Gazpacho soup + some nice bread [simply store the soup in a Tupperware container]
* instant-noodle salad

As a uni student I just spread some Vegemite, or Marmite, on some flatbread.

I recommend varying things up. Eating the same thing over and over gets boring, unless it's pizza.
Hey ... cold pizza, not that bad actually. Just cook it the day before and eat it with some rucola (rocket) leaves.

The best that i know is this. :D
Also, keep an eye for opportunities like this. ;)

"Food delivery shuttle coming in, open airlocks." :D

... and keep them open, protein = farts!

why not buy mre's instead ?
they come in presealed bags and everything in an mre is sealed as well

and they are no doubt easier to buy then astronaut food

like here https://www.amazon.com/Meals-Ready-Genuine-Military-Surplus/dp/B005I5ML36

"Eat Snickers if you are hungry! You are not you."

Tactical Bacon is also a solution.

I usually do this for mobile lunches or some combination of:

Hard-boiled eggs
apple or banana
ziplock of mixed nuts
ziplock of pretzels or crackers

a slice or 2 of beef jerky is also usually a great addition