• I have an SF setting called Vaster that I use for a table-top roleplaying game that I GM. The campaign is set in a star system settled by three different human cultures and one culture that is multi-species. I've given each a different cuisine:

    The most hidebound culture is also the one that uses the most processed food. Things are rather bland, and all meat is vat-grown. The other cultures find it easy to terrorize them at table.

    Another culture is all about cultivating individual ability. They are less likely to take guests out to a restaurant than to show off their own cooking skills. Their cuisine is the spiciest.

    The third lives on ice-age planets, grows a lot of vegetables in greenhouses, and uses a lot of dairy from sheep and (genetically reconstituted) mammoths.

    The multi-species culture of course has multiple cuisines:

    One race are one-ton amphibious squid-like things whose native technology revolves around their chemical control of their own digestion. Their "cuisine" is a LOT ... of anything remotely organic.

    Another is a race of, basically, intelligent tigers. No hands. Lots of raw meat. Earthlings introduced them to cooked meat, which was great.

    Of the four cultures, the multi-species one makes the most use of the Commensality, a galaxy-wide fraternal organization that promotes community by staging street parties and big pot-luck suppers.

  • In an SF setting with a variety of aliens, one of my races has "alternation of generations," a process in real biology in which an sexual generation produces asexual children, who produce sexual grandchildren. It is commoner in plants, and doesn't occur in vertebrates, on Earth. But it's a feature of Drot biology.

    A Drot marriage consists of a husband, a wife, and two "spouses" (the asexuals). That's a "full" marriage. Typically, people start with "part marriages" and build up.

    In the same setting, human medical technology is able to fix everything except the more advanced forms of death, so rejuvenation is standard. As one of many cultural results, most marriages are "term" marriages and simply end after a stated time. A 10-year contract is regarded as rather frivolous. 50-year is rather standard. Divorce is very rare because, after all, you can just wait for the contract to expire and then not renew. Permanent marriage is a religious requirement for some, a romantic ideal for others, and an impractical idea for yet others.