Pearl onion

The pearl onion (Allium ampeloprasum var. sectivum or A. ampeloprasum 'Pearl-Onion Group'), also known as button onion, baby onion or silverskin onion in the UK, is a close relative of the leek (A. ampeloprasum var. porrum), and may be distinguished from common onions by having only a single storage leaf, similar to cloves of garlic. In French they are known as oignon grelot. One English-speaking reference also mentions the term petit poireau antillais.