I try, yes.
If it's made out of kosher ingredients, using kosher utensils, by a Jew, and not on Shabbos, then yes.
Kosher
This is a Jewish phrase to insult another Jew that is Kosher, if you see Why is there a Jew on that couch? if you say couch while the u is silent it sounds like Koush which then falls on Kosher, Kosher means you can only eat certain kinds of meat and food and animals.
If it was made from kosher fish, with kosher equipment, under the supervision of a Jew who keeps kosher, and comes in tamper-proof packaging, then yes.
if they are observant, only kosher.
Not if you're an Orthodox Jew.
Yes, he is a Hasidic Jew and Keeps Kosher
Yes, tuna is a kosher fish. Canned tuna must be kosher certified though.
look up "Kosher meals" on Google - that should help answer...
because they wont give me their gold
It can be. If it's for a religiously observant Jew it not only has to be kosher, it also has to be 'meshuval' meaning that it has been pasteurized.
Religiously observant Jews will only eat food that is kosher.