How to cook onions for the perfect curry

Many good recipes often start with "Cook the onions until they are soft and translucent"... but why do we do this and what does this actually mean?

Onions are a staple ingredient in most savoury recipes and are used across the world in different cultures. This humble vegetable adds a mellow, sweet depth and our taste buds would notice if it was absent from a dish.

Cooking onions is important for two main reasons. Firstly, it makes them easier to digest, as the high acidity of onion drops during the cooking process. Secondly, the sugars are released and broken down into smaller molecules that our tastebuds can detect - more cooking results in more sweetness. The longer you keep them bubbling away on the hob - slow and steady - the better it will be for digestion and your finished dish. 

And this is why it's important not to rush this process. The softened, translucent stage takes at least 10 minutes and, if a recipe is calling for caramelising, that takes closer to 45 minutes. It sounds like a hassle but it's worth it for a much better end result. 

Here's a rundown of the steps we take to perfectly cooked "soft and translucent" onions, without having to stand-and-stir constantly:

1. Dice the onion, add a pinch of salt and give it a mix. This will draw out some of the moisture and make it easier to soften.
2. Add a good glug of oil and chunk of butter. You can do one or the other, but we find a mix of both gets the best results.
3. Start them cooking over a medium heat. Once sizzling, turn the heat down to low and put a lid on. Allow them to cook slowly over the gentle heat, stirring every few minutes. Add a splash of water if it's sticking to the pan or browning.
4. After 10 minutes, take the lid off, turn the heat back up to medium and cook for a further minute or two.

A final top tip? If the onion smells especially strong or you find the flavour of onions overpowering, give them a quick rinse under cold water before cooking to make them milder.

See more Curry Cooking Tips below:

Top Tips for Making a Better Homemade Curry

Slow Cooker Curry Tips - A Slow Cooker Recipe for Success

How to Cook a Healthy Curry in 30 Minutes or Less