If you didn't feel even slightly unwell, this wasn't a true indian street vendor. The roadside 'dhabas', informal restaurants that are typically family run, don't charge very much and are typically not great for hygiene are the ones I am talking about. Those are far worse than lcc plane food trust me. You have to be very careful. Anyway, hopefully you get to fly Vistara next time you go to India. If you are going into delhi, consider it. It's worth the extra money.
Maybe - I might just fly direct into Calcutta though - that's where my mom's family is. But maybe then CCU-DEL I'll try them. IDK, it'll be a while before we go on such a long trip again.