Keo me xung is a Vietnamese candy made with peanuts and sesame seeds usually eaten during Tet (Lunar New Year), although it can be devoured year-round as a sweet treat paired with a cup of hot tea.

There’s an art and a science to making halvah, says Richard Radutzky, president of the 118-year-old candy company Joyva. Some steps in making the sesame-based confection are nearly impossible to ...