Many types of onions are given the name scallions, but a true scallion has a straight, firm base. When you see a curve at the end, it’s a telltale sign that you’re looking at an immature onion picked before a bulb can form. Scallions are also much milder in flavor than other onions, so you might want to think twice about substituting. It could alter the taste of a dish. More often than not, a recipe that calls for scallions usually asks for them to be minced. Mincing is just a finer version of chopping or dicing.
