Caramelized onions bring a boost of bold flavour to almost any dish. They are a cook’s secret weapon and naturally bring any recipe up a few notches. The downside to making caramelized onions is that they take a L-O-N-G time to make, and require more effort than most are willing to put forth on an ordinary weeknight. While there are cheat-sheet versions that use balsamic vinegar to create the signature golden hue that’s associated with slowly cooked onions, they don’t taste as sweet or have the same supple texture as properly caramelized onions.
Which is why we’re sharing an additional method of caramelized onions wish using a slow cooker!
Not only will this method yield enough onions to store a few recipe’s worth in your freezer, but it mostly requires hands-off cooking time that can be done overnight… even while you sleep. For properly caramelized onions, you need to leave them in the slow cooker for 10-12 hours, so if you prep them and pop in the countertop appliance after dinner, they’ll be ready by the following morning.
Serves Makes 1 cup546
- 4 cups chopped onions (about 2 large or 4 small onions)
- 2 tablespoons butter
- 3-5lbs. yellow or Vidalia onions
- 2 Tbsp. olive oil
- 1 Tbsp. melted butter
- ½ teaspoon kosher salt
- ½ teaspoon granulated sugar
- 1 bay leaf
- Melt butter in a large Dutch oven or skillet over medium heat. Add onions; cook and stir until onions begin to soften, about 4 minutes.
- Reduce heat to med-low and cook, stirring occasionally until onions become golden in colour and sweet (about 30 to 40 minutes).
- Peel, halve and thinly slice the onions into half-moons.
- Place prepared onions into the slow cooker, filling the insert three-quarters full.
- Drizzle the olive oil and melted butter over the onions. Add the salt, sugar and bay leaf and toss to combine.
- Cover the slow cooker and cook on low for 10 hours. Stir occasionally, if time permits (i.e. you’re not sleeping). After 10 hours, the onions should be soft and golden brown. There will be a lot of liquid in the bottom of the insert. You can discard it, or keep it and it to soups, stews, chilis, etc.
- Remove the onions now, or cook for an additional 2-4 hours with the lid slightly ajar for a jammier, richer consistency. Check on the onions every 60-90 minutes, and stop cooking when they taste and look the way you want. Remove bay leaf before using onions.
- Caramelized onions can be stored in the fridge for up to a week, or in the freezer for up to three months.
- Caramelized onions stored in an airtight container will last up to 2 weeks in the fridge.
- If the onion sugars on the bottom of the pan start to brown to quickly, or burn, just add a splash of water and stir up the brown bits – this is called deglazing. Also, reduce the heat a bit.
How to Use Caramelized Onions
Now that you have a big batch of caramelized onions on hand, here are some ideas for how to use them:
- Top a pizza with caramelized onions, spinach, bacon and Gruyere.
- Add to grilled cheese sandwiches.
- Stir into mashed potatoes with a dollop of horseradish.
- To make a classic onion chip dip, place one cup of caramelized onions and ½ each cream cheese, mayonnaise and sour cream in the bowl of a food processor. Season with a pinch of cayenne and pulse until the dip reaches the desired consistency.
- Add caramelized onions to salad.
- Stir them into almost any pasta dish. Here’s a brilliant recipe to try: Pasta with Yogurt and Caramelized Onions.
- Pile on top of bruschetta.
- Add to a frittata with black olives, sun-dried tomatoes and feta.
- Use them to spiff up rice, risotto, burgers and hot dogs.