Welsh onion, also known as scallion or spring onion, is a versatile vegetable used in various cuisines for its subtle onion flavour. It belongs to the species Allium fistulosum and has flat, solid leaves and a mildly pungent bulb. In China, it is called "cong" and is used in stir-fries and dumplings. In Japan, it is known as "negi" and is used in soups and stews. Other synonyms for Welsh onion include green onion, salad onion, long onion, and Japanese bunching onion. Whatever name it goes by, Welsh onion adds depth and complexity to any dish it is added to, making it a staple in many kitchens around the world.