How to make caramelized onions

a hand holding a spoon full of caramelized onions over a jar full of them

Caramelized onions are slowly cooked, caramelizing their natural sugars to develop a depth of flavor that is so SO good! These melt in your mouth onions are like onion jam. I love adding caramelized onions to burgers, sandwiches, pasta dishes, etc.

Course Side Dish, topping

Cuisine American

Keyword how to, kitchen basics

Prep Time 15

Cook Time 45

Servings 1/4 cup servings

Calories 128kcal

Author Lauren LeBlanc

Equipment

sharp knife
cutting board
cast iron skillet or stainless steel pan
metal spatula or wooden spoon

Ingredients

3 pounds onions, sliced or diced yellow, red, white, Vidalia, Walla Walla, Spanish, sweet, etc
1 tablespoon extra virgin olive oil
2-3 tablespoons deglazing liquid water, vinegar, broth, beer, wine, etc
salt to taste
sweetener optional - sugar, brown sugar, agave, honey, etc.
1 tablespoon unsalted butter

Instructions

ADD THE ONIONS: Heat butter or oil in a large cast iron skillet or stainless steel pan over medium low heat. Add the onions to the pan in batches, while stirring. As the onions wilt down, add more onions until all onions can fit in the pan.
SALT: Add salt to taste. Start off with less than you think you will need. The onions will shrink down a lot, and you can always add more salt later.
STIR AND SCRAPE: Continue stirring the onions every few minutes, scraping up any fond (the browned bits that stick to the bottom of the pan) that forms as you go. Onions will go from white/yellow, to golden, to golden brown, to dark rich brown as they caramelize.
DEGLAZE: After about 30 minutes of stirring and scraping, onions should be almost dark brown. Add a few tablespoons of your deglazing liquid of choice to the pan and use it to scrap up the fond from the pan. Onions are done when they are rich dark brown and jammy in texture. You can also finish off with a tablespoon of butter for more flavor.
SWEETEN: (OPTIONAL) You can also add more sugar or sweetener to the pan with the deglazing liquid.
ENJOY: Add caramelized onions to burgers, sandwiches, steaks, chicken, in a dressing, on a charcuterie board, on hotdogs or brats, patty melts, quiche, omelets, pastas, soups - they are good in just about everything.

Notes

This is a non-recipe recipe, meaning there are no exact amounts of the ingredients used. The above measurements are just a starting point, but you can adjust quantities as you see fit.
3 pounds of raw onions yields 1.5 cups of caramelized onions.
The secret trick to caramelizing onions is to allow them to stick to the pan just long enough for them to start caramelizing, but move them again before they start burning. You want to stir frequently, but not constantly.
Nutrition information does not include deglazing liquid or additional sweetener used.

TROUBLESHOOTING:

Onions are browning too quickly - Turn the heat down, and add a splash of deglazing liquid or water. Stir more frequently.
Onions aren't browning quickly enough - Turn the heat up slightly and stir less frequently.
Onions are browning unevenly - Stir the onions more often. You also may need to cut smaller onion slices next time.
Too much liquid - Turn the heat up slightly and allow the onions to cook longer, allowing liquid to evaporate. Continue stirring and scraping up any fond on the pan.
Caramelized onions turned out mushy - I actually like my caramelized onions to be a little mushy - more like onion jam. To prevent your caramelized onions from getting mushy, try making thinner slices next time. Also overcooking and adding too much deglazing liquid can yield mushy caramelized onions.

Nutrition