Caramelized Onion Recipe

Main

1. 1

   Prepare onions

   Peel and halve the onions lengthwise. Slice each half into 3–4 mm (about 1/8" to 1/4") thick slices to yield approximately 4 cups of sliced onions.

2. 2

   Heat fat

   In a large, heavy-bottomed skillet or sauté pan set over medium heat, add the butter and olive oil. Heat until the butter is melted and the fat shimmers but is not smoking (about 1–2 minutes).

3. 3

   Start cooking onions

   Add all sliced onions to the pan and stir to coat them evenly in the fat. Spread them into an even layer and let cook, undisturbed, for 3–4 minutes to begin softening and releasing moisture.

4. 4

   Season and stir

   Sprinkle the sugar and 2 teaspoons of the kosher salt over the onions and stir to combine. Reduce heat to medium-low. Continue to cook, stirring every 4–6 minutes to prevent sticking and to encourage even browning.

5. 5

   Deglaze and control color

   After about 20–25 minutes, the onions will have softened and started to brown. If fond (brown bits) is building on the pan, add half of the water or broth (about 30 ml) and scrape the pan with a wooden spoon to loosen those caramelized bits. Continue cooking. Repeat adding liquid in small increments as needed to keep the onions moist and prevent burning.

6. 6

   Deepen flavor

   When the onions are a deep golden-brown and very soft (total cooking time 35–45 minutes), stir in the optional red wine to deglaze further, scraping the pan, and cook until the wine mostly evaporates (1–2 minutes). Add the balsamic vinegar if using and cook another 30 seconds to incorporate.

7. 7

   Finish and season

   Taste and adjust seasoning: add the remaining 1 teaspoon kosher salt (or to taste) and add the black pepper. If onions are too bitter or not sweet enough, add a pinch more sugar. Stir well and remove from heat.

8. 8

   Cool and store

   Let the caramelized onions cool for 10–15 minutes. Use immediately, or transfer to an airtight container and refrigerate for up to 5 days, or freeze in portions for up to 3 months.