Onions are naturally sweet and when you cook them oven an extended period of time, the natural sugars in the onions brown and caramelize. You’re left with sweet, buttery onions that are full of deep, rich flavors.
Use these onions on brats or steaks, for soups, dips, pizza or whatever. Heck, I’ll even eat them by themselves, they’re so good! Just keep in mind that any amount of onion you start with will reduce down like crazy. Make sure you have enough for everyone. 5 large raw onions will reduce to about 2 cups of caramelized onions.
If you make a big batch, caramelized onions will keep in the fridge for up to a week in an air-tight container. They freeze really nicely too. Keep small portions of onions in your freezer to thaw when needed.
Slice off the root and top ends of the onions and peel them. Cut the onions in half. Lay the cut side down and slice the onions lengthwise to desired thickness.
Use a wide, thick-bottomed sauté pan and coat the bottom of the pan with olive oil and butter (about 1 teaspoon per onion). Heat the pan on medium to medium-high heat until the oil is shimmering. Add the onion slices and stir to coat the onions with oil. Spread the onions evenly over the pan and let cook, stirring occasionally. After 10 minutes, sprinkled some salt and sugar over the onions. Add a bit more butter and a splash of water to keep the onions from drying out.
Let the onions cook down for 30 to 60 minutes, stirring every few minutes. As soon as the onions start sticking to the pan, let them stick a little and brown, but then stir them before they burn. After the first 20 to 30 minutes you may want to lower the stove temperature a little, and add a little more oil if your onions are on the verge of burning. Scrape up any brown bits that may have formed on the bottom of your pan. Continue to cook and scrape until the onions are a rich, browned color.
At the end of the cooking process you might want to add a little balsamic vinegar or wine to help deglaze the pan and bring some additional flavor to the onions.