Nutrinional software

Hey everyone,

I know some people here are into nutritional topics, so maybe you can help me out.

I am looking for a simple way of measuring macro and micro nutrients on a meal, mostly for salads (meaning, I am interested in the values for basic ingredients like "onion" and "cucumber" and not specific brands or pre-made stuff).
I am also aware all the nutritional tables in existence are averages and they vary a lot, but that's OK as I am only wanting those averages.

Well.... It seems to not be as easy to do it as I thought. I started with F-Droid apps, which I was expecting would be straightforward.... The one that came close to what I wanted was Energize, but it lacks the hability to simply create and store basic salad recipes without inputting everything manually.
In Trisquel I tried Cronometer, and it's mostly OK, but I can't find out how to import a food element from USDA tables to it! :(
I also looked around online for an option but can find anything that fits what I want (or websites require lots of JS and google stuff and I would prefer to go without it).

So, what software do you guys use for this purpose?
Thanks in advance!