GIVEAWAY: Win a De'Longhi Stilosa Manual Espresso Machine! →

When it comes to onions, we like ours beautifully caramelized, but we hate having to keep an eye on them as they cook on the stove, constantly coming to stir them and make sure they don’t burn. Given how many other awesome things our slow cookers have churned out, we figured this was the perfect time to put them to the test and see if it wasn’t 100 times easier to whip up a batch of sweet, brown onions without lifting a finger.

After trying it out a few times – with a few additions here and there – we’re happy to say we’re thrilled with these onions! Chop them up and add some butter (and brown sugar or balsamic vinegar, if you feel so inclined), then toss ‘em in the cooker and let them do their thing. You can then use them in a deliciousFrench onion soup, or to top off agreen bean casserole…you can’t go wrong!

Slow Cooker Caramelized Onions

Yield: 3-4 cups


  • 4 pounds yellow onions, peeled and finely chopped
  • 1/2 cup (1 stick) unsalted butter, cut into pats
  • kosher salt and freshly ground pepper, to taste
  • brown sugar, optional
  • balsamic vinegar, optional


  1. Place chopped onions in slow cooker and arrange butter pats on top.
  2. Cover slow cooker and cook on LOW for 8 hours, stirring once or twice in between.
  3. After 8 hours, check onions and see how they look and if they’re tender.Optional: season with salt, pepper, brown sugar or balsamic vinaigrette.
  4. Cover again, leaving lid just slightly ajar, and cook for another 2 hours, or until onions have reached desired tenderness and cooking juices have mostly evaporated.
  5. Store in an air-tight container and serve hot or cold.

Recipe adapted fromFamily Fresh Meals

Subscribe to 12 Tomatoes