Not many organizations that I know of host large dinners cooked by their own members anymore, more so in the form of historical food based presentations. While I have seen the occasional small dinner with some historical basis, sometimes catered and other times by professional cooks, the Society for Creative Anachronism (SCA) is one that actually hosts large feasts on a fairly regular basis at events held over many parts of the world and done so mostly by people with no formal training in the kitchen what so ever.
The fact that a large portion of SCA kitchens are staffed by non-professionals is not a horribly bad thing, creating these feasts, as well as attending them, is a part of the groups ideology about learning through participation in one shape or form. Of course, safety is also of concern and because of this, more and more kitchens are requiring people take courses on kitchen safety which has become a wonderful asset. Though remember, even professional kitchens are not fool proof.
The growing problems seem to be coming with food allergies and other special food concerns. While many professional kitchens today offer vegetarian options, allergies are often even too challenging for those establishments, never mind the SCA run kitchen. While the cooks have learned to manage cross contamination that would cause regular health concerns and keeping separate vegetarian options (already a feat in designing a medieval feast), these kitchens are often, in no way, set up to deal with various food sensitivities.
Things to consider here:
-you can visit the kitchen, however food is often prepped and sometimes made in a different kitchen
-you may trust the cook, however many hands are at work
-sometimes a specific item can be omitted from a feast but this is sometimes difficult to do without compromise and can become impossible should too many items become an issue without sacrificing the quality of the entire feast (quality including maintaining "periodness")
-cooks are often relegated to home, or home style, kitchens to create a meal far surpassing what these kitchens were meant to do.
-these feasts often provide meals at a fraction of the cost of eating out, to do this, this means they are produced on a budget.
-stuff happens! Budgets collapse, food goes missing, ingredient lists go missing, kitchen staff bails out, people wander into the kitchen (bringing potential for contamination and other issues), kitchens change and equipment goes missing... and that is just from my own experience.
Now this isn't to say that such feasts will not be able to handle the occasional food related issue, but we should keep in mind the difficulties of providing what we ask under many of the circumstances given.