Go to Johnny Fasullo's Sausage and Braciole stand on the south-west corner of Mulberry and Grand. When it's not too busy, they keep a tray of long green and yellow roasted peppers out so you can help yourself to putting them on your sandwich.
My wife and I always make a b-line for that stand.
I know, I know: "it ain't what it used to be" "I wouldn't be caught dead at San Gennaro" "It sucks" ...whatever.
Get over it. It's a New York institution. It's fun. You might as well check it out. Again.