How to Caramelise Onions

Oh the magic of slow cooking over low heat.  There’s nothing that takes to the caramelisation process better than onions — trust me on this one.


This is such a simple process — and it requires time but little effort.  It’s the perfect thing to have going on the stove when you’re cooking something else and can check in every so often (see how technical that is) for a little stir.

Once you’ve got caramelised onions on hand (and they keep really well in the fridge for about a week) you have a whole new deep & rich flavour for quickly spicing up your meals.  Try them on a sandwich (maybe in place of these roasted onions in a Roasted Portobello & Onion Sandwich with Blue Cheese), or to make your favourite pasta dish explode with caramelised goodness.

They’re amazing in calzones and on pizzas, and I bet you could make awesome wonton ravioli with caramelised onions as either the filling or the sauce.

But the best way I like them?  On toasted bread.  Like a spread.  But smellier.  Oh yeah.

How to Caramelise Onions
Each onion will yield only about 1/4 of its fresh size in caramelised form, 3-4 onions yield about 1 cup once caramelised.

  • 4 onions, thinly sliced (any kind work here, I used red because I had them on hand)
  • 2 Tbsp. olive oil
  • 1 generous pinch of salt

Over very low heat in a very large pan, sweat the onions in the oil until they become translucent.  Then keep going.  Don’t try to cheat and turn the heat up, you need to keep the heat low and the process slow to get the best flavour.  Keep the onions on the heat for about 45-60 minutes total, stirring occasionally.


I find that as the onions reduce down in size, they cook best when you smush them all together into the centre of the pan.

When they are all browned and sweet and delicious (after about 45-60 minutes), remove from heat and stir in the salt.  Enjoy with friends, so you’re not the only stinky one!


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Categories: Gluten-Free, Side Dish, Snack, Vegan, Vegetarian


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6 Comments on “How to Caramelise Onions”

  1. bonne_santé
    November 13, 2010 at 1:00 am #

    I’m so ashamed that I used to turn my nose up at onion, no matter how lovingly caramelized…all those wasted years!
    This looks amazing Lindsay, as always!

  2. October 10, 2012 at 2:29 pm #

    I never take the time to do this but I will from now on. I ate caramelised onions at a restaurant that really knew how to do them well and they were so delicious I swore I’d learn how to propersly caramelize onions! No more cheating for me!

    • October 10, 2012 at 2:31 pm #

      I find it’s one of those perfect things to have on the stove while you get other stuff done. And they are AWESOME on pizza.


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