This. Is. Life. Changing. I love the flavor and depth of caramelized onions so much but I usually do not have 40+ minutes to wait for them to start from raw, astringent crescents and get to where they are going in a skillet on the stovetop. If I did have 40+ minutes of time I would probably use it on something else (like a pedicure, just sayin’).
This method is so easy, it isn’t even really a recipe. All you need is a slow cooker, a small drizzle of olive oil, and a 5lb bag of yellow onions. In the morning, I sliced the entire bag and dumped it into my large slow cooker. I drizzled in a bit of olive oil and tossed to coat all of the onions. I set the cooker on low and let it go all day, stirring every few hours. At dinnertime, I drained off all of the liquid that had seeped out of the onions. At this point they were a pale golden color. I put the onions back in the dry slow cooker, set the lid ajar, and continued to cook on low overnight. In the morning I had the most glorious, burnished mound of savoriness.
My favorite way to store these caramelized beauties is frozen so they keep the longest. I use a 1/4 c. measuring cup and mound them onto a baking sheet.
Stick in the freezer until solid and then transfer to a plastic freezer bag.
I use these for everything; scattered on a pizza, on a chicken breast with grated gruyere for a riff on french onion soup, or heck in soups themselves!
Minimal effort and fast flavor whenever you need it.