“Tía tô is so easy. It survives the rain with no protection from nets or glass. And there’s always a market for it.” Tía tô (known in the west as red perilla) is commonly found on side plates at bún chả and bún ốc stalls. It’s purple and green and has a big, earthy flavor. It sparkles when dunked in fish sauce and munched with spades of noodles.