Caramelised onion

Caramelised onions are made by slowly cooking sliced onions with olive oil, brown sugar, vinegar, and thyme, transforming them into a sweet and savory topping. Perfect for enhancing burgers, steaks, soups, and pizzas, they add depth to any dish.

23 Nov 2025
Cook time 30 min
Prep time 10 min

Ingredients:

2 tbsp olive oil
2 onions
1/3 cup brown sugar
1/3 cup vinegar
1 tsp fresh thyme

Caramelised onions are a versatile and flavorful addition to many dishes, from burgers and steaks to soups and pizzas. By cooking onions slowly in a mix of olive oil, brown sugar, vinegar, and fresh thyme, you can bring out their natural sweetness and create a rich, savory topping or ingredient.

Instructions:

1. Heat the Oil:
- Place a large, heavy-bottomed skillet over medium heat.
- Add the 2 tablespoons of olive oil and let it warm up until it shimmers.

2. Prepare the Onions:
- Peel and thinly slice the 2 onions (about 320g).
- Add sliced onions to the warmed oil in the skillet.

3. Cook the Onions:
- Stir the onions to coat them evenly with the olive oil.
- Reduce heat to low-medium and cook for 10-15 minutes, stirring occasionally, until the onions are soft and translucent.

4. Add Brown Sugar:
- Sprinkle the 1/3 cup (72g) of brown sugar over the softened onions.
- Stir well to combine, ensuring all the onions are coated with sugar.

5. Add Vinegar:
- Pour in the 1/3 cup (72g) of vinegar.
- Mix thoroughly to combine the vinegar with the onions and sugar.

6. Add Fresh Thyme:
- Finely chop 1 teaspoon (5g) of fresh thyme and add it to the skillet.
- Stir well to distribute the thyme evenly through the mixture.

7. Caramelize the Onions:
- Continue to cook the mixture on low-medium heat, stirring occasionally, for an additional 20-30 minutes.
- Allow the onions to caramelize slowly, achieving a rich, brown color and a sweet, tangy flavor. Adjust the heat if necessary to prevent burning.

8. Finish and Serve:
- Once the onions are fully caramelized, remove the skillet from the heat.
- Let the mixture cool slightly before serving.

Caramelizing onions is a simple but rewarding process that adds depth and complexity to many recipes. By following these steps and tips, you'll be able to create beautifully caramelized onions that will enhance any dish they're added to.

Caramelised onion FAQ:

How long does it take to caramelize onions?

Caramelizing onions typically takes about 30-45 minutes. Initially, cook them for 10-15 minutes until soft, then add brown sugar and vinegar, and continue cooking for another 20-30 minutes until they achieve a rich, brown color.

What type of vinegar is best for caramelizing onions?

You can use various types of vinegar, including balsamic, apple cider, or white wine vinegar. Each will impart a different flavor, so choose one that complements your dish.

Can I store leftover caramelised onions?

Yes, store leftover caramelised onions in an airtight container in the refrigerator for up to 5 days. They can also be frozen for up to 3 months—just make sure to cool completely before freezing.

What can I use as a substitute for brown sugar?

You can substitute brown sugar with granulated sugar mixed with a little molasses (1 tablespoon molasses per cup of sugar) or use coconut sugar for a similar flavor profile.

How do I know when the onions are done caramelizing?

The onions are done when they are deeply browned, have a rich, sweet flavor, and a sticky, jam-like texture. Taste them to ensure the sweetness has developed to your liking.

Tips:

- Use high-quality olive oil to enhance the flavor of the onions.

- For best results, use a heavy-bottomed skillet to ensure even cooking and prevent burning.

- Slice the onions evenly to ensure they cook uniformly.

- Be patient; caramelizing onions takes time, and rushing the process can lead to uneven cooking or burning.

- Stir the onions occasionally to prevent sticking and to ensure even caramelization.

Nutrition per serving

2 Servings
Calories 220kcal
Protein 1.50g
Carbohydrates 50g
Fiber 3.39g
Sugar 45g
Fat 14g

Caramelised onion