Adapted from seriouseats.com
Caramelizing onions is a bit labor- and time-intensive, but the results are so worth it! Note that the onions will lose as much as two-thirds of their volume as the water they contain evaporates and they slowly brown.
- Start with 2 onions, peeled and halved. Put cut side down and cut thin, even, lengthwise slices.
- Heat a pan (preferably nonstick) or skillet over medium heat, then add approximately 3 tablespoons of olive oil or a combination of olive oil and butter (enough to coat all the onions).
- Once the oil is shimmering, add onions and a good pinch of salt. Stir to coat all the onions, and keep stirring around every 30 seconds so the onions cook evenly. After about 5 minutes, reduce heat to low and stir every minute or so. If the pan gets dry, add a little more oil.
- After about 10 minutes, you’ll see the first hints of amber. You may stop now or continue cooking to achieve a deeper color—another 10 minutes is optimum, but keep going a bit longer if desired—just don’t burn them!
- When finished, transfer the onions to a cool plate or bowl to stop them cooking. You may add them to a recipe as soon as they’re done or store them covered in the fridge for several days. Enjoy!