Pearl onions are tiny white onions about 3/4 inch (2 cm) in diameter, added whole to stews and other dishes. They are also known as pickling onions.
To peel pearl onions:
Using a small, sharp knife, trim off the root ends. Cut a shallow X in each trimmed end, to keep the onions whole during cooking. In a saucepan, combine the pearl onions with plenty of water to cover. Bring to a boil; boil for about 2 minutes, then drain. When the onions are cool enough to handle, slip off the skins by squeezing gently with your fingers.For other onion varieties, see boiling, green, Maui, red, Vidalia, Walla Walla, white, and yellow onions and leeks and shallots.