If you only reach for scallions as a garnish, you're missing out on the fresh flavor they bring to all kinds of dishes, ttoommyy says on Chowhound.
Mellower when raw than red or yellow bulb onions, scallions (also known as green onions) can do great things to leafy salads, guacamole, and uncooked salsas and condiments like Momofuku's ginger-scallion sauce, "so simple, yet so good," egit notes. Scallions also happen to be the best choice for make-ahead tuna or chicken salads, since they won't turn bitter like raw bulb onions do, masha points out.
Grilled or sautéed whole, scallions make a great side for meats, the traditional accompaniment to Mexican carne asada. And eateatate cooks a big pile of chopped scallions in oil on low heat until they're soft and golden brown, then adds soy sauce and toasted sesame oil to toss with noodles (the garnish: chopped raw scallions, cilantro, and toasted sesame seeds).