The trend supposedly takes inspiration from Chinese coffee shops and involves mixing a few spring onions into an iced coffee.
The suggested way to prepare this is with a latte. You’ll start with those cut soring onions in the bottom of the glass, then muddle them, then add your ice & milk. Plus I suppose a few onions on top for garnish.
The reactions are mixed, as you can see below. I would have to agree with the guy who called it ‘horrific’.