this post a few days ago at From The Bookshelf. As soon as I saw it, I knew exactly what I would be doing with the crate of onions sitting in my kitchen. I'd previously intended to prep and freeze or dehydrate them, but this has changed everything.
Perfectly caramelized onions were created with little to no effort on my part. I may never use a skillet for this task again. I filled a 4 quart crockpot to the top with sliced onions and it reduced to a perfectly filled pint jar of caramelized onions. I will be doing this again over the weekend and freezing the caramelized onions in 1 cup portions to use as I need them.
Caramelized Onions In The Crockpot
6-8 large yellow onions
3 tablespoons butter
3 tablespoons olive oil
pinch of salt
1-2 teaspoons balsamic vinegar, optional
Set the crockpot on high heat and add the butter and olive oil. Slice the onions and fill the crockpot with them. Add a pinch of salt. Toss the onions to coat with the oils. Leave the lid OFF and walk away. I stirred the onions occasionally throughout the day, scraping the sides each time.
Total cooking time was approximately 8 hours, but that will vary for different slow cookers and crock-pots. When the onions are browned and soft to your liking, add a bit of balsamic vinegar. For what it's worth, I completely forgot to add this. The onions were delicious, but I bet they would have been even better with the vinegar.
FREEZER TIP: Portion the onions into 1/2 cup portions and store aritight in a ziploc bag. Thaw in the refrigerator.