Sautéing onions concentrates their natural sugars so they take on a glorious sweetness as the onions soften. Cook them longer, and they eventually caramelize into a golden brown. When you know how to sauté onions to bring out that natural sweetness, you’ll start adding them to your cooking much more often.

Sautéing onions simply means cooking them in a pan with butter, oil, or other fat until the onions are tender. This cooking method is super flexible—there is no best onion to sauté or ideal-size pieces. You can use any type of onion and any cut. Some recipes call for cooking the onions until tender but not brown, while others continue cooking until caramelized or golden. We’ll show you how to do both, as well as offer pointers on purchasing onions, ways to cut them, and how to use sautéed onions.

How to Sauté Onions

In a large skillet or pan heat oil or butter over medium-high heat until hot. Use about 1 tablespoon fat per small to medium onion (you can use just about any fat, so follow these directions for how to sauté onions in butter, vegetable oil, olive oil, or another fat). If you want to sauté onions without oil, be sure to use a nonstick pan, and add a small amount of water or vegetable broth to help keep onions from sticking.

Add chopped or sliced onions and cook for 5 to 7 minutes or until tender, stirring frequently with a wooden spoon or heatproof spatula. That’s how long to sauté onions to remove the harsh onion flavor and just barely start to sweeten the cooking onion. If desired, cook a little longer until edges just start to brown to bring more sweetness. Remove from heat and use as desired.

If you want to learn how to sauté onions and peppers, the process is pretty similar. So both veggies cook in a similar amount of time, cut your onions and peppers into similar-size pieces. Then follow the instructions above and cook the onions and peppers together in oil until both are tender (it should take closer to 7 minutes).

Test Kitchen Tip: The onions will cook more evenly if you don’t crowd them. Stir the onions frequently and keep an eye on the heat. If the heat is too high, the onions can burn.

Easy Ways to Use Sautéed Onions:

Now that you know how to sauté them, put your cooked onions to use in all kinds of recipes. Here are ideas to get you started.

  • Burger Topper: Top burgers or panini sandwiches with sautéed or caramelized sliced onions.
  • Potato Bar: Add sautéed sliced or chopped onions to your potato-bar toppings.
  • Omelet Filling: Tuck onions inside an omelet along with blue cheese and chopped pear, or try shredded Swiss cheese and chopped ham.
  • Side Dish: Stir fresh spinach into a pan of sautéed onions and cook just until the spinach wilts. Season with salt and ground black pepper.
  • Appetizer: Spread toasted French bread slices with goat cheese and top with sautéed onions and a sprinkle of snipped fresh thyme.

How to Caramelize Onions

Cooking onions longer at a lower heat results in onions that are soft and golden brown. This breaks down the natural sugars so the onions taste extra sweet. We recommend using butter for the best flavor.

  • Thinly slice 2 onions. Sweet onions, such as Vidalia or Walla Walla, are preferable, but any kind of onion will work.
  • In a large skillet melt 2 tablespoons butter over medium-low heat. Add the onions. Cook, covered, for 13 to 15 minutes or until the onions are tender, stirring occasionally. Uncover the skillet; cook and stir over medium-high heat for 3 to 5 minutes more or until onions are golden.

Purchasing and Storing Onions

Before you sauté an onion, be sure you’re starting with a good-quality product and prepping it correctly. Use these onion pointers to get started:

  • Choose onions that are firm, heavy for their size, and free of blemishes and soft spots. Avoid those that are starting to sprout.
  • 1 small onion = 1/3 cup chopped; 1 medium onion = 1/2 cup chopped; 1 large onion = 1 cup chopped
  • Store onions loosely in a container in a cool, dry, well-ventilated place, preferably not the refrigerator. Fall and winter onions store longer (several weeks) than the more delicate and sweeter spring and summer onions.

How to Chop and Slice Onions

Rinse the onion thoroughly under cool tap water. On a cutting surface, use a chef’s knife to slice off the stem and root ends. Remove the papery outer skins and cut the onion in half from the top end to the root end.

To Chop

Place each onion half, flat side down, on the cutting surface and make side-by-side vertical slices from stem end to root end. Holding slices together, cut across the slices, making tiny pieces. If you’re looking for speed, this is the best way to sauté onions because the small pieces will cook more quickly than larger slices.

To Slice

Place a peeled onion on its side on a cutting surface and use a chef’s knife to cut it crosswise, making slices as thin as desired. Discard the top and root slices.

To Slice into Wedges

On a cutting surface, cut the peeled onion in half from stem to root end. Place the flat side of a half down and cut from end to end, angling toward the center to make desired-size wedges.

No matter how you slice it, sautéed onions and caramelized onions make a great addition to a lot of different recipes. Sautéed onions can also be the start of a delicious dinner, as they’re usually included in stir-fry recipes and recipes with ground meat, like meatloaf. Once you’ve mastered this cooking skill, there’s no limit to the number of recipes you can upgrade with sautéed or caramelized onions.

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