Caramelized Onion

Slice an onion finely.

Not too finely though.

Toss all of the ingredients into a heavy pan. Turn it to somewhere around medium-low.

Keep an eye on it for a bit as the butter melts and the onions begin to sweat. Your only goal here is to cook the onions very gently, stirring every few minutes or so, until they just melt and turn very lightly brown, very slowly.

It's not uncommon to finish with a little vinegar. just pour in a splash and stir over heat until it's mostly evaporated. as the onions cook, you can also throw in a little thyme or a chunk of star anise to add even more complexity.