Every Italian serves an antipasti/antipasto when company arrives. A traditional antipasto has meats, cheese, olives and anchovies but you can really create any antipasto to make it different or your own.
When I was at Shop Rite (E. Hartford, CT) these portobello mushrooms stood out and I decided to make a new version of an antipasto! Everyone enjoyed it and so did I..
When ready to serve drizzle balsamic reduction.
Reduce heat to a medium-low and simmer until it is reduced by half and thick. Stir or whisk often to prevent any burning at the bottom of the pan.