Slow-Caramelized Onions
Sweet yellow onions are cooked low and slow until they transform into a jammy, deeply browned, and incredibly flavorful condiment. Perfect for topping burgers, steaks, or folding into dips.
For 8 servings
4 steps. 50 minutes total.
- 1
Step 1
- a.Start cooking the onions
- b.Heat olive oil in a large, heavy-bottomed skillet or Dutch oven over medium-low heat.
- c.Add the thinly sliced onions, salt, and optional sugar. Stir well to coat everything evenly.
- d.Cook for about 10 minutes, stirring occasionally, until the onions have softened completely and become translucent.
- 2
Step 2
- a.Caramelize the onions slowly
- b.Reduce the heat to low. Continue to cook for 40-50 minutes, stirring every 5-7 minutes.
- c.Be patient as the onions slowly transform from pale, to golden, and finally to a deep, rich brown color.
- d.Scrape the bottom of the pan as you stir to prevent sticking and incorporate the flavorful browned bits.
- 3
Step 3
- a.Deglaze and finish
- b.Once the onions are deeply caramelized and jammy, pour in the balsamic vinegar.
- c.Stir constantly for about 1 minute, scraping the bottom of the pan to lift any remaining browned bits.
- d.Continue cooking until the vinegar has fully evaporated and the onions are glossy.
- 4
Step 4
- a.Cool and store
- b.Remove the pan from the heat and let the onions cool slightly before using.
- c.Serve warm as a topping or store in an airtight container in the refrigerator for up to a week.
What to keep in mind.
6 tips from the recipe — small details that make a real difference to the final dish.
- 1Use a wide, heavy-bottomed pan like cast iron or stainless steel for the most even heat distribution.
- 2Don't rush the process! Low and slow is the secret to true caramelization, which develops sweetness without burning.
- 3Slice your onions to a uniform thickness to ensure they all cook at the same rate.
- 4Make a large batch. Caramelized onions freeze beautifully in ice cube trays for easy, portioned use later.
- 5For an even sweeter result, use sweet onion varieties like Vidalia, Walla Walla, or Maui.
- 6If the onions start to stick too much before they are fully browned, add a tablespoon of water to help release them from the pan.
Adapt it for your goals.
Healthy
Use only 1 tablespoon of olive oil and deglaze with water instead of balsamic vinegar to reduce calories and sugar.
quickQuick
For a faster version, cook on medium heat, stirring more frequently. They will be done in 20-25 minutes but won't have the same depth of flavor.
veganVegan
This recipe is naturally vegan. Just ensure your brand of balsamic vinegar is certified vegan if you have concerns about processing aids.
gluten freeGluten free
This recipe is naturally gluten-free. Most balsamic vinegars are safe, but check the label to ensure it is certified gluten-free.
Why this is on our healthy list.
Rich in Antioxidants
Onions contain quercetin, a powerful antioxidant that helps combat inflammation and supports overall cellular health.
Flavorful & Low-Calorie
Provides a huge boost of sweet and savory flavor to meals for very few calories, helping to make simple foods more satisfying.
Source of Prebiotics
Onions contain prebiotic fibers that nourish beneficial gut bacteria, supporting a healthy digestive system.
Frequently asked questions
In moderation, yes. Onions themselves are low in calories and a good source of antioxidants like quercetin. The main calories come from the cooking oil, but they provide immense flavor, reducing the need for high-fat sauces.