One night each week, Somebody People, a vegan restaurant on South Broadway, throws an everyone-is-welcome dinner party. The Sunday Supper, as it’s called, is an all-hands-in effort, with every member of the kitchen staff cooking something and, often, executive chef Justin Freeman stepping aside to let someone else take the lead in an effort to encourage experimentation. The menu-which can skew Japanese, Thai, or even Irish, although the restaurant usually serves rustic Mediterranean fare during the week-is determined by the desire to use up whatever ingredients are in-house at the time.