Caramelized onions

Caramelized onions are a sweet and rich addition to many dishes, made by slowly cooking red onions in olive oil until golden. This simple method enhances their natural sweetness with a touch of brown sugar and vinegar for a flavorful finish.

11 Feb 2026
Cook time 30 min
Prep time 5 min

Ingredients:

2 tbsp olive oil
2 red onions
2 tsp brown sugar
2 tbsp vinegar

Caramelized onions are a delicious addition to a wide variety of dishes, offering a rich and sweet flavor that enhances any plate. Whether you're adding them to burgers, salads, sandwiches, or even as a side dish, this simple recipe can elevate your meal to the next level.

Instructions:

1. Prepare the Onions:
- Peel the red onions and cut them in half lengthwise.
- Thinly slice the onions into half-moons.

2. Heat the Oil:
- In a large skillet or frying pan, heat the olive oil over medium heat. Swirl the pan to ensure the oil coats the surface evenly.

3. Add the Onions:
- Add the thinly sliced onions to the pan. Stir to coat the onions with the oil.
- Spread the onions out in an even layer in the pan.

4. Cook the Onions:
- Cook the onions over medium heat, stirring occasionally, for about 10 minutes until they begin to soften and turn translucent.
- Keep an eye on the heat to make sure the onions aren't browning too quickly. Adjust the heat as needed to avoid burning.

5. Add Brown Sugar:
- Sprinkle the brown sugar over the onions. Stir to combine. The sugar will help with the caramelization process, giving the onions a deeper flavor and richer color.

6. Caramelize the Onions:
- Continue to cook the onions, stirring occasionally, for another 20-25 minutes. Patience is key here; allow the onions to cook slowly to develop a rich, caramel color and sweet flavor.
- If the onions start to stick to the pan or cook too quickly, reduce the heat slightly and add a splash of water to deglaze the pan.

7. Add the Vinegar:
- Once the onions are deeply caramelized, pour in the vinegar. Use the vinegar to deglaze the pan, scraping up any browned bits from the bottom.
- Stir and cook for another 2-3 minutes until the vinegar has evaporated and the onions are glossy and deeply flavored.

8. Serve or Store:
- Transfer the caramelized onions to a bowl and let them cool slightly.
- Use immediately as a topping for burgers, sandwiches, or pizzas, or incorporate into dishes like pasta, salads, or soups.
- If storing, allow the onions to cool completely before transferring to an airtight container. Refrigerate for up to one week or freeze for longer storage.

With just a few simple ingredients and a bit of patience, you can create a batch of caramelized onions that will add depth and flavor to many different dishes. Follow these tips, and enjoy the sweet, savory result of your efforts in the kitchen.

Caramelized onions FAQ:

How long does it take to caramelize onions?

Caramelizing onions takes about 30-35 minutes in total. Start by cooking them over medium heat for about 10 minutes until they soften. Then, add brown sugar and continue cooking for another 20-25 minutes until they reach a deep caramel color.

What should I do if my onions are browning too quickly?

If your onions are browning too quickly, reduce the heat to prevent burning. You can also add a splash of water to the pan to help deglaze and keep them cooking slowly.

Can I use other types of onions for caramelizing?

Yes, while the recipe calls for red onions, you can use yellow or sweet onions instead. Each type will yield a slightly different flavor, but they all caramelize well.

How do I store leftover caramelized onions?

Allow the onions to cool completely before transferring them to an airtight container. They can be refrigerated for up to one week or frozen for longer storage.

What can I substitute for vinegar if I don't have any?

If you don't have vinegar, you can use lemon juice as a substitute. It will provide a similar acidity to balance the sweetness of the caramelized onions.

Tips:

- Use a non-stick or heavy-bottomed pan to ensure even cooking and prevent burning.

- Slice the onions thinly for quicker caramelisation.

- Stir occasionally but not too frequently, allowing the onions time to brown.

- Adjust the heat as necessary to avoid burning, keeping it mostly medium-low.

Nutrition per serving

2 Servings
Calories 88kcal
Protein 1.51g
Carbohydrates 18g
Fiber 3.52g
Sugar 12g
Fat 14g

Caramelized onions