For those of your working in the office, do you bring your own lunch or buy your lunch?
I guess I spend about 10 - 30 Fr per day on lunch at the office. In the past, I’ve taken lunch sometimes when I had leftovers or when I had cravings for certain foods. But it was a hassle to cook in the morning, bring it with me, wash the stuff and bring the containers back so I’m usually lazy and buy.
What are your favourite foods to bring? What are your tips?
In our office, we have a culture of eating out at restaurants, but we are only in the office two days a week. Nevertheless, it adds up. A meal at a restaurant costs around CHF 30. For several months now, I have been trying to break this habit and bring food from home once a week.
Now, whenever I cook at home, I always cook for more people. So for example instead of cooking for two, I cook for four. I then freeze the remaining portions.
I bought this freezer for that purpose:
https://www.galaxus.ch/en/s2/product/spc-gs3703-stand-alone-87-l-freezers-25432019
And I bought many of these:
https://www.ikea.com/ch/en/p/ikea-365-food-container-with-lid-square-glass-plastic-s39269120/
https://www.ikea.com/ch/en/p/ikea-365-food-container-with-lid-rectangular-glass-plastic-s89269071/
(Regarding containers: Definitely buy glass containers. If you eat from them with a knife and fork, you can throw away the plastic ones after a year. Blastik gets cut and becomes ugly.)
Before I leave the house to go to work, I just grab whatever I feel like from the freezer.
The same in my home office.
Advantages:
It feels like a supermarket freezer / shelf at home with ready-made meals (just pop them in the microwave and you’re done). Except that these were prepared by myself. The only problem is that when everyone else goes to the restaurant, I sometimes feel left out (FOMO). On the other hand, I also like the extra time I have at lunchtime, which I can use to go for a walk or do something else. It could even be considered an improvement in quality of life (maybe).
I have a simple rule. For the 1-2 times per week that I go to office, I spend max 10-12 CHF per lunch. I havent crossed this limit for the past 2 years (until 31-Dec-2023, I was working 100% from home).
If there are leftovers from the previous evening and they are healthy, I prioritise taking those leftovers. Last 2 years, I spent approx. 400 CHF on office lunches per year.
I always used to pack my lunch when I worked in an office, ~10 years, and before that for ~6 years of PhD and postdoc. We had a pub lunch every second Friday but it was paid by the Prof 
Normally I bring food 2 out of the 3 days I am at the office, and it’s almost always leftovers from family dinner one or two days before. Cooking for this would be very inefficient use of my time, but cooking a bit more for dinner and then using the leftovers pushes me to not gobble up everything left on the table for dinner, which is healthier than my instinct of keeping zero water food. Once a week is nice to eat with all folks who always go out eating anyway, or I would never interact with some of them.
This year I started being more conscious with the food. Like markus, I bought a fridge and take the time to meal prep. Yesterday we prepared the food for like three hours, but I have everything ready for at least two weeks. It’s not cooked, but it’s compartmentalized to make it easier to cook.
Also bought a rice cooker a few months ago. I wanted a fancy Zojirushi, but they don’t sell it here and the EU model is crazy expensive and not made in Japan. So, I settled for a Xiaomi at 50.-
Nice investment.
I’d say it’s really worth it if you’re 2+ people. When I’m alone, I don’t feel like cooking and a few times my veggies rotted because I ate a lot outside.
I do not have any particular tips apart from the fridge if you have the space. It’s a game changer to store meat. Aside from that, it gets personal. I don’t mind eating rice, beans, and meat for the whole week. But I know a few people cannot.
For me, a mix between canteen, take-out by myself and bring from home. Rarely a lunch-menu in restaurants. It depends a lot on what’s available, as well as the social setup.
What to bring from home? Most often whatever is (intentionally) “left-over” in the fridge from dinner 1-3 days ago and easily be heated-up. This assumes a break room with microwave and seating.
Any container will do (packed right after cooking), but ideally stack-able, and ready for oven, microwave and freezer. Mostly glass, but it’s heavy to carry around.
I rarely batch-cook, and if do it’s for home.
Flat, plate-sized boxes (those with little “compartments” to separate food) seem to get better results in micro-waves, but are less convenient to transport and general use.
In the office, maybe the container gets a quick rinse, otherwise it goes in the dishwasher at home.
Any sort of sandwich or salad doesn’t need heating and is more flexible and easier to take outside, but needs some effort to prepare.
Quick and dirty option for emergencies: Some instant noodles that just need some hot water.
If I cook bigger portions for dinner/lunch,
I rather leave them for the next day’s dinner,
So I don’t need to cook (long) again in the eve. 
At work most days I take a smaller lunch at the canteen (10ish CHF),
Occasionally a “full fledged” one if I have a lunch date with colleagues.
I got lucky: my favorite thing (mixed bowl from buffet) at the staff restaurant costs slightly less than 10 CHF. I prioritize spending lunch breaks with colleagues, hence I will join them for wherever else they might wanna go from time to time.
Last work place, everyone brought food from home (mostly leftovers for me) or bought it outside. We all ate at a big table in the office building. I loved the fugality and social exchange of it.
We usually batch cook on Sunday and Wednesday early evening. It is about 2h and 1:30h sessions of cooking. The rest is mostly warming up food or cooking green veggies.
We often eat our own prep for lunch and dinner.
I mostly cook with rice cooker, instant pot (rack of ribs, beef stew, butternut-squash soup). my wife loves grilled veggies in the oven so she bakes first cakes for desert then we pile 4 Pyrex rack of potatoes, sweet potatoes, fennel…
A generous portion of home made dish should cost 4-5 chf.
Most of my colleagues eat at the local cafeteria where we have microwave and fridge so we can eat together. Plat du jour and dessert cost14-16 chf
during corona i started systematic foodprep: in case we cook at home (and it’s not the quick pasta with pesto) i just scale up to 8+ portions and directly package it for indivdual lunch boxes.
my freezer is full of it^^
Ideally lots of veggies + where applicable some small bits meats. Rica/ pasta can be quickly done in the morning with close-to-zero time/ cleanup effort, as storing cooked pasta in the freezer is abit of a waste 
favourite prep meals:
the finances are clear: for CHF 20 i can typically have one lunch in the canteen/restaurant or ~8 lunch boxes (+effort)
The Migros next to my place of work has those tray of foods where you pay based on the takeout box size. 7.8 the small one, 9.8 the big one. Small one is largely enough for me.
It’s often pastas, but it’s good enough for me for the twice a week I go.
Sometimes I take leftovers from dinner (depending on what we do, we try to cook more), but there’s competition from my partner. 
Since I started working in St. Gallen, I prepare all my meals for the week (lunch and dinner; 3 lunches, 2 dinners) on Sunday and/or Monday evening. I make simple things like roasted vegetables with chicken. Pasta with various sauces: curry, pesto, cream, Bolognese, and I often add vegetables on the side. In short, anything that is simple to cook in a short amount of time and that I enjoy cooking. I also always prepare extra so that my girlfriend can have lunch to take away.
So I carry 5 Tupperware containers in a rucksack with my work computer and a second bag with clothes (work, sports, leisure). I have been doing this diligently for almost a year now and I intend to continue.
Why? I think the food in my employer’s cafeteria is poor value for money. I can prepare much better meals for less money, using better quality ingredients too.
Yes, so far this year I have always brought my own lunch.
Tip: Just make more food on the night before.
What I like: Pasta, it’s very versatile, if you use wholewheat it is healthy. Curries, very versatile.
Right now I don’t go too often to the office, so I join the restaurant with the others.
I’d like to bring my own lunch when that changes. But similar to Parkinson’s law, my appetite expands to the amount of food cooked. So there are little left overs.