Sweet Onion Purée

FAQ
Can I skip the brown sugar?
Yes, the onions already bring natural sweetness. The sugar just enhances depth.
Can I make this ahead?
Yes, it actually tastes better the next day.
Do I need a blender?
A blender gives the smoothest result, but a food processor works.
Can I make it vegan?
Yes, use olive oil instead of butter and vegetable broth.
Chef’s Tips
- Take your time with the onions, colour = flavour here. Don’t rush the caramelization.
- Season lightly early, then adjust at the end for balance.
- If it starts sticking, lower the heat and add a splash of broth.
- A tiny splash of vinegar at the end wakes everything up (balsamic or sherry works best).
- Blend while warm for the smoothest, silkiest texture.

Sweet Onion Purée
This sweet onion purée is slow comfort in a spoon. Sweet onions are cooked down until golden and jammy, then blended into a silky, rich purée with a savoury backbone. It’s simple, but it hits that deep, restaurant-style flavour that makes everything it touches taste better, from roasted meats to sandwiches and veggies.
Equipment
- Blender or Food processor
Ingredients
- 2 large sweet onions (peeled and chopped)
- 2 tbsp butter
- 1 tbsp olive oil
- 1-2 tbsp brown sugar (optional, to taste)
- ¼ cup chicken or vegetable broth (plus a little more as needed)
- Salt and pepper (to taste)
- Optional: 1 tsp balsamic or sherry vinegar (for finishing) (for finishing)
Instructions
- Heat butter and olive oil in a saucepan over medium heat.
- Add onions and a small pinch of salt. Cook slowly for 10–12 minutes until soft and translucent.
- Lower heat slightly and continue cooking until onions turn deep golden and jammy, stirring often (15–20 minutes).
- Add brown sugar (if using) and cook for another 2–3 minutes to deepen flavour.
- Pour in broth, scraping up any bits from the pan. Simmer gently for 10–15 minutes until very soft.
- Remove from heat and let cool slightly.
- Blend until completely smooth, adding a splash of extra broth if needed to loosen.
- Season with salt and pepper to taste.
- Finish with a small splash of vinegar if desired for balance.
- Serve warm as a sauce, spread, or topping.
Notes
- Perfect as a base for gravies, soups, or pan sauces.
- Spoon over mashed potatoes, roasted meats, or grilled vegetables.
- Mix with mayo or sour cream for a quick dip or sandwich spread.
- A little goes a long way, it’s concentrated and rich.
- Fridge: Cool completely and store in an airtight container for up to 7 days.
- Freezer: Freeze in small portions or ice cube trays for up to 2–3 months. Thaw overnight in the fridge.
- Reheating: Warm gently in a saucepan over low heat. Add a splash of broth or water if it thickens too much.
Tried this recipe?
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