In my survey for the best Italian subs in Los Angeles, I came across a handful of delis, all in the San Fernando Valley, where a chopped relish involving onions and tomatoes — and at some places pickles — supplants the more common thinly sliced tomato and onion on an Italian sandwich.

Where did this Valley relish — and I’m calling that because it doesn’t seem to have an official appellation — come from? According to Salvatore Palilla, who has owned Santoro’s Subs in Burbank since 1996, the chopped vegetables came with founder Pat Santoro from Boston.