The phrase "potluck supper" refers to a gathering where each person brings a dish of food to be shared with everyone. It means that everyone contributes and brings something different, creating a diverse and varied meal. Full definition
She ended up moving to the area for a while, riding on fire trucks, visiting Smith and Bundick in jail, getting to know residents at church potluck suppers and digging deep into the area's past, present and future, even reading a book about the chicken industry «that is more interesting than any book about chicken farming has a right to be.» (bookpage.com)
When religious studies departments are the caterers, the smorgasbord will boast different delicacies, in different proportions, than those provided by a theological banquet or a church - sponsored potluck supper. (religion-online.org)
True, they are bound together by sharing in potluck suppers too, but there is a difference. (religion-online.org)