Onions Yellow Onions standard “gold” and usually the cheapest in the market. If you use a recipe that does not specify what type of use onion, yellow onion is the best. Yellow onion is extremely durable, and its flavor is complex and spicy. It also has more sulfur than other varieties of onions, so they are more nimble, and is more difficult to eat raw. One advantage of this is that it keeps onions for a very long time. It is best for: dishes you cook for a long time over low heat, such as soups, including French onion soup, stock, risotto, sauces and stews. Any saute well.