I don't normally do recommendations but I feel that this information is one which I'm karmically bound to share with others.
Like most of my business colleagues in Warsaw, I spent a lot of time (and money) looking for a really good catering service that would deliver a "home-cooked" experience, culinary excellence (Read: Not generic, over-cooked restaurant meals) along with a personalised service for parties, seminars, meetings and conferences.
After years of searching, I've discovered a hidden gem called Yoshi catering; the food is fabulous and the service even better. I'm not sure if I'm allowed to post a link here but here goes nothing: Protected content
Please note that I do not have any business relationship/affiliation with Yoshi Catering; I'm sharing this information purely for the culinary benefit of other InterNation members...Smacznego!