Canon is not very forthcoming on the subject of food (although we know that actual fruit and coffee beans do exist, but as rare luxuries, that nutrient packs exist, and that Vila knows what Avon means when he refers to a sandwich).
Terran farming is probably a bad idea because of radiation contamination, but there probably are hydroponic farms. But there are agricultural planets (see Star One). I figure that there are lots of kinds of food analogs to supplement whatever fresh foods can be obtained. (There are also distilleries to make green booze.)
The assumption I use in writing fanfic is that on the Liberator, there are regular sit-down meals for the crew, and that everyone has to take turns cooking and washing up (although this degree of civilized amenity has probably broken down on Scorpio and maybe on Xenon Base). In a way this is irrational--they couldn't all be awake at the same time--but I think Blake would insist on it as a means of instilling group cohesion. I think the others would also find it reassuring, although several of them wouldn't admit it. Nova figures that they heat things up for themselves in advanced microwave ovens...but that doesn't seem very companionable.
I've seen plenty of stories involving "pleasure planets" but somehow no one except me seems worried about where you can find a really good restaurant on shore leave...
-(Y)