Make Ahead Caramelized Onions

Directions

1. 1
   Put the butter in a 4 quart or larger slow cooker insert.
2. 2
   Separate the onion slices into rings and add them to the slow cooker, lightly packing them down.
3. 3
   Sprinkle the salt over and cover with the lid, (the cooker will be quite full).
4. 4
   Cook on high until the onions are very soft and a deep caramel color, about 10 to 12 hours, stirring once or twice.