Choose the right onions;
The best onions for caramelising are sweet onions, such as Vidalia, Walla Walla, or Maui onions.
These onions have a higher sugar content and will caramelise more easily.

In Australia and New Zealand, the most popular onions for caramelizing are brown onions and red onions.

Brown onions have a strong, pungent flavour that mellows out when caramelized, while red onions have a slightly sweeter taste that also works well when caramelized.

Slice the onions thinly;
Thinly sliced onions will cook more evenly and caramelise faster.
Use a sharp knife or a mandoline to slice the onions into thin, even slices.

Heat the pan;
Use a large heavy-bottomed pan, such as a cast iron skillet, and heat it over medium-high heat.
Add a tablespoon of oil or butter to the pan and let it melt.

Add the onions;
Add the sliced onions to the pan and stir to coat them in the oil or butter.
Spread them out evenly in the pan.

Season the onions;
Add a pinch of salt and pepper to the onions to enhance their flavour.
You can also add herbs or spices, such as thyme or cumin, for extra flavour.

Cook the onions;
Cook the onions over medium-high heat, stirring occasionally, until they start to soften and turn golden brown.
This can take anywhere from 15 to 45 minutes, depending on the amount of onions, the thickness of the onions and the heat of the pan.

Add liquid;
If the onions start to stick to the pan or burn, add a splash of liquid, such as water, broth, or wine, to deglaze the pan and prevent burning. This will also add extra flavour to the onions.

Continue cooking;
Continue cooking the onions, stirring every couple of minutes, until they are deep golden brown and caramelised.
They should be soft and sweet, with a rich, complex flavour.

Serve and enjoy;
Caramelised onions are a delicious addition to many dishes, such as burgers, sandwiches, pizzas, and salads.
They can also be used as a topping for soups or stews, or as a flavourful side dish. Enjoy!