If a ben Noach invites a non-religious ben Yisrael to his home for Torah study(let's say they study the seven laws of Noach together) and the ben Yisrael gets hungry, and he's going to not eat kosher food anyways, can or should the ben Noach offer him food from his non-kosher kitchen?
The answer to this question depends on whether non-Jews have the obligation of לפני עיוור לא תתן מכשול (the prohibition of placing a stumbling block before the blind). I address this question in this answer.
In summary, the prohibition of lifnei iver--even according to the more stringent opinion--only applies to non-Jews for halachot that they are obligated in. Since non-Jews are not obligated to keep kosher (except for the prohibition of eiver min hachai, but we can leave that aside for now), there is no halachic prohibition for a non-Jew to provide non-kosher food to a Jew.
As I mentioned in the linked answer, however, a Jew eating non-kosher food is definitely problematic from his perspective even if it is not from his host's perspective. As such, it certainly couldn't hurt for a non-Jewish host to go beyond the letter of the law and provide kosher food. It would prevent the Jew from sinning.
Feed him fresh fruits and vegetables. Wash and inspect for insects. Kosher concerns solved.