spring onion

US /ˈsprɪŋ ˌʌn.jən/
UK /ˈsprɪŋ ˌʌn.jən/
"spring onion" picture
1.

a young onion, especially one picked before the bulb has begun to swell, used in salads and cooking

:
Chop the spring onions finely for the salad.
Garnish the soup with fresh spring onions.