Servings: Makes about 1 quart

6 tablespoons (90g) unsalted butter 6 tablespoons (90g) unsalted butter
3 pounds (1.4kg) yellow or mixed onions, sliced 1/8 inch thick (see note) 3 pounds (1.4kg) yellow or mixed onions, sliced ⅛ inch thick (see note)
Kosher salt and freshly ground black pepper Kosher salt and freshly ground black pepper

In a large stainless steel saucepan, or in 2 large stainless steel or cast iron skillets, melt butter over medium-high heat until foaming.
Add onions and cook, stirring occasionally, until softened, about 8 minutes.
Lower heat to medium-low, cover and cook, stirring frequently, until onions are very sweet and a rich golden-brown color, 1 to 2 hours.
If browned onion juices on bottom of pot threaten to burn, add 1 tablespoon (15ml) water, scrape up browned bits, and continue cooking; add water whenever needed to prevent burning.
Season with salt and pepper.

You need to cut the onions lengthwise (like all cuts should be north pole to south pole) to avoid super mushy onions if you cut them the more common way. I like to cut the onion in half (lengthwise) and then cut off the ends (north and south poles) and then carefully cut that into about 5 sections lengthwise.  You need to cut the onions lengthwise (like all cuts should be north pole to south pole) to avoid super mushy onions if you cut them the more common way. I like to cut the onion in half (lengthwise) and then cut off the ends (north and south poles) and then carefully cut that into about 5 sections lengthwise.