If you’ve been to a wedding, bar mitzvah or corporate event in the Boston area, chances are you’ve dined with East Meets West. Venues across the city have given the full-service caterer a preferred-vendor stamp of approval for catering intimate dinner parties and galas for thousands. Some of the menus’ greatest hits: mushroom dumplings, mini lobster rolls and banh mi, Kobe beef sliders and plum-and-goat cheese crostini.