The appetizer that my mom always made for company was baked clams, and if there were both red and green peppers in the mix, we knew it was party time. I think of it as the type of appetizer your mom would make when company was coming over. More like the “sneaking rum punch at your parents’ Christmas party” kind.
Stuffed mushrooms have a vintage cocktail party vibe, but not the swanky “sipping old-fashioneds at the 21 Club” kind.