Tag Archive for confit onions

Confit Onions in the Slow Cooker

I am not a fan of raw onions. Served to me on a salad or a burger, I will pick them off. When you cook the onions, however, it’s a whole different ballgame.

Onions have lots of naturally-occurring sugars, so when you cook them down at a low heat, the most magical thing happens to them. They caramelize, and take on this gorgeous light-brown colour. They become sweet and savoury all at the same time.

confit onions

Yeah, there were a few tears this day…

I make these regularly, and keep them in my fridge. They come out and get added to grilled cheeses (my favourite), any kind of wrap or burrito, burgers, or as a garnish to a piece of baguette topped with a chunk of brie.

You can even can these and give them out as gifts.

I love doing mine in the slow cooker. It just is so easy. Slice ’em up in the food processor, add them along with a few other ingredients, and let it go. 8 hours later, voila! Perfect caramelized onions.

A quick word of warning: it’s kind of shocking how much these cook down. A slow cooker full of onions will net you a cup or two of the good stuff, but it really is a condiment, so you’ll likely only use a tablespoon or two at a time.

Slow-Cooker Confit Onions


  • approximately 2 lbs onions (really, any kind, although purple and Walla Walla are sweeter)
  • 2 tbsp butter or olive oil
  • 1 tsp coarse sea salt
  • 1-2 tbsp port wine
  • 1 tbsp sweetener–maple syrup, brown sugar or molasses
  • 1 tsp thyme, or a couple of fresh spigs


  1. Prep the onions by halving and peeling them, then thinly slicing them into half-moon rounds. I did the slicing in the food processor, but you could also do it on a mandolin, or by hand. You will have a large pile of onions.
  2. Dump the onions, along with the rest of the ingredients, into your slow cooker, and turn it up on high. Stir everything together well.
  3. Allow to cook for about 6 hours, stirring occasionally. They onions are done when they achieve a nice caramel colour. Remove the sprig of thyme, if using. If the onions are really watery, you can take the lid off of the slow cooker and cook them for another hour or so until the water evaporates and the onions thicken. Alternatively, you can finish them in a saucepan on top of the stove, boiling them, uncovered, until you get the right consistency.
  4. Store in a jar in the fridge. My 2 lbs of onions boiled down to make enough to fill a 500-ml mason jar.

Also, check out my friend Melissa’s version of this recipe.