BaÂ·sidÂ·iÂ·oÂ·myÂ·coÂ·ta. A phylum of fungi characterized by a spore-bearing organ, the basidium, that is usually a clavate cell that bears basidiospores after karyogamy and meiosis. Some mycologists have raised the class Basidiomycetes to the phylum or division level.
Add the onions to the skillet and increase the heat to medium-high. Cook until they begin to turn dark brown and somewhat soft, about 5 minutes. Add the oil and a pinch of the fine sea salt; continue cooking until the onions are soft and caramelized, about 5 minutes longer.. Soft, dark brown onions in five minutes. That is a lie. Fully caramelized onions in five minutes more.
Prep the Onions. The best onions to use for caramelizing are sweet onions, since they tend to be juicy with a mild, sweet taste. Some popular sweet varieties include Maui, Vidalia, and Walla Walla onions. For four to six 1/3-cup servings, start with two large onions and peel away and discard the outer papery layers. Slice the onions into thin slices or cut into 3/4-inch chunks. Melt the Butter. Butter offers the richest flavor, but you can caramelize onions in other fat such as margarine or olive oil.