Slow Cooker Caramelized Onions make it easy to turn onions into something rich and flavorful. Just add everything to the crock pot and let time do the work! Perfect for soups, burgers, dips, and more.
Peel and slice the onions finely. You can do it with a knife, mandolin or food processor.
Add the onions to the slow cooker (it will be quite full, but will reduce as it cooks). Add the butter and sugar and gently stir to combine slightly.
Cook on low, with the lid on, for 8-10 hours.
If it’s not cooking overnight, you can give it a stir every few hours, but this isn’t essential.
Your onions should be brown and caramelised. If it still has a lot of moisture, you can remove the lid and cook it for a further half hour or so until it evaporates.
Notes
To make it into French onion soup, add half of the caramelised onions (2 cups/450g), to a large pot along with 2 tablespoons of butter.Heat for a few minutes, then stir in 1 tablespoon of flour and cook for a further minute.Deglaze the pan with 1 cup of white wine and let it bubble for a minute, then stir in 4 cups/950ml vegetable or beef stock, 2 bay leaves and ½ teaspoon dried thyme.Bring nearly to the boil, then reduce the heat and simmer for 20 minutes.Spoon the soup into oven-safe bowls, top with toasted bread, then add cheese and broil/grill for a few minutes until the cheese is bubbling.