But it doesn't have to be even.
Everyone takes a spoon of the dishes they want, taking care not to take too much so everyone who wants some gets some.
People eat their food and chat.
When plates are (nearly) clear, anyone who wants some more has seconds, again giving others chance if they want some too. Second time around, some people will be full, others will want a bit more of dish A, others dish B etc.
For anything where there's not much left, before taking the last of it, just say, anyone else want any more of this? If not, it's fair game, if yes, share what's left or order some more.
End result is that everyone has had the amount and type of food they want, which will likely naturally be different amounts/combinations.