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caramelized onions in a soup ladle

Caramelized Onions

These soft, sweet onions are a perfect base for omelettes, soups, pastas, pizzas, salads and sandwiches. Give yourself a full hour to look after their transition from raw onion to final masterpiece–there are no shortcuts.

Makes about 250 g/9 oz (based on 700 g/25 oz starting onion weight),
or about 1 cup by volume, tightly packed


onions: about 500-750g/17-26 oz (adjust the amount of oil, salt, vinegar below based on amount of onions)
oil: 3-4 Tbsp oil
salt: 0.5-0.75 tsp salt
balsamic vinegar: 2-3 tsp



  • Heat a large saute pan to medium high.
  • While the pan is heating, cut the root and tip end off of each onion. Peel the onions, taking care to get all the papery and tough skin away. Clean your cutting board of any skin–we don’t want any of this to get included.
  • Cut the onions in half from root to tip, then rotate 90 degrees and cut each half crosswise into thin slices. (Tip: We want to cut crosswise slices as this cuts through the onion fibers allowing the water to escape and the caramelization to happen.)

Phase 1: Initial Cook, 5 minutes

  • Add the oil and allow to heat.
  • Add the onions and toss with the oil until all the onions are coated. We don’t add salt yet–we want to keep moisture in the onions until they have a chance to cook on the inside.

Phase 2: Steam the Onions to Cook Through, 10 minutes (15 minutes total)

  • Reduce the heat to medium and cover the pan. Stir once after 5 minutes.
  • Note: we of course don’t want steamed onions as the end product, but this steaming stage enables the onions to cook internally so that they don’t dry out and burn in the next phase while caramelizing.

Phase 3: Caramelize the Onions, 45 minutes (60 minutes total)

  • Reduce the heat to medium-low. Uncover the pan and stir the onions every 2-3 minutes.
  • After 10 minutes in this phase, add the salt and mix to combine.
  • After 30 minutes in this phase, mix in the balsamic vinegar and scrape up any fond that has developed on the bottom of the pan. If the mixture is too dry, add a bit more oil or butter.
  • Keep stirring every few minutes until the onions are deep brown, about 45 minutes in this phase, or 60 minutes overall.
  • Keep in the fridge for a few days in an airtight container, or freeze for later use.