- 1 large yellow onion (~ 12 ounces)
- 1 tablespoon extra virgin olive oil
- 1/4 teaspoon fine salt
- Optional: 1-2 tablespoons water (as needed – see instructions)
- Preheat a 12-inch cast iron skillet on the stovetop on medium heat.
- While the pan heats up, cut the onion in half through the root (vertically). Remove the outer layer of skin and trim off both ends of both halves of the onion. Cut the onion into 1/4-inch slices (with the knife positioned vertically in the same way as when you cut the onion in half – so that halfway through cutting it would slice through the root if the root was still intact). Make sure your slices are all the same size thickness for even cooking.
- Once the pan is hot add the onions, oil and salt. Toss well so the onions are evenly coated with the oil and salt. Cook for five minutes until the onions start to soften and some begin to brown. Once this happens turn the burner to low-medium heat (halfway between low heat and medium heat) and cook for 40 minutes. Continue to toss the onions every couple minutes as they cook on low-medium heat. Keep the onions in one even layer throughout the cooking process so all onion slices are touching the pan.
- The onion slices will start to caramelize and turn golden brown. Continuing tossing throughout the process monitoring the onions closely toward the end to prevent burning. With a cast iron skillet the onions should caramelize nice and evenly. If the pan starts to dry out toward the end you may add one tablespoon of water and toss immediately. This isn’t usually necessary but can help to prevent burning toward the end.
- Once the onions are all golden brown throughout each entire slice you can use immediately. I love to use caramelized onions in soups, on pizza, in dips (French Onion Dip and hummus in particular), dressings, in pasta sauce or in pasta whole, in tacos, on veggie burgers as a topping, or with mashed potatoes. It has a distinctly sweet umami flavor that makes any dish unforgettable!
- Save leftovers once fully cooled in a small airtight glass or silicone container in your refrigerator for up to one week. You can freeze up to two months.
If doubling the recipe you may need to use a larger skillet or you may need to toss more often. It is important that the skillet is not overcrowded or the onions will steam instead of caramelize. I like to make sure that all onions are touching the bottom or side of the cast iron skillet to ensure they cook evenly and at the same speed.
For faster results, dice the onions instead of slicing them. When diced they will take about 25 minutes to caramelize. Just be sure to stir often and keep the heat as low as possible so they don’t burn.
- Method: Stovetop
Keywords: how to make caramelized onions