Maybe you're thinking of baba ganoush, which is a dip with a charred eggplant and tahini base. I've made it with eggplant broiled in the oven, and it's fine, but I'm sure the taste is different if they're charred over a flame. (Even though you discard the charred shell either way.) That said you could easily accomplish that with a kitchen torch, the kind also used to finish creme brulee or (if you have a big torch) sous vide meats.