This recipe for caramelized onions yields about 8 cups, but that depends on how long you cook them. I prefer a deep rich color in onions that still hold some shape. Try to resist cooking them to mush. Pack as many onions as you can into your slow cooker for maximum efficiency as they freeze well. Any variety of onion will work, as the onions sweeten as they cook.
7 to 10 pounds onions, peeled and thinly sliced
1 Tbsp kosher salt
1 stick butter, sliced into 8 pieces
1. Pack as many onions as possible into your slow cooker. If you can’t get them all in at first stir them in after the onions have begun to reduce.
2. Sprinkle the top with the salt and sliced butter.
3. Cook on high for 3 hours, stirring once after the butter has melted,
4. Reduce the heat to low and continue to cook for 10 to 12 hours longer, or until the onions are a deep golden brown.
5. Remove the onions to a large, wide pan and cook on medium heat until the liquid had reduced, stirring occasionally.
6. Divide into portions and freeze as needed.