I guess you'll have to pack up with supps when you get back to Hungary.
For the cold lunch you can make a salad of brown rice (prepared but cold), squash, red onions, olive oil, salt, bok choy (swe: salladskål), cucumber, broccoli, cauliflower, eggplant, celery, asparagus (swe: sparris) and some herbs.
(you may exchange the rice to quinoa, buckwheat or similar)
Some avoid carbs as much as they can with the candida-regimen but my perception is that you must have carbs to have energy to move and keep up a healthy circulation.
But the carbs have to be of a complex structure like the ones in brown rice, buckwheat, low GI-vegetables etc..
Some may be sensitive to brown rice or alike but there are other options too like amaranth and quinoa.