6 large onions (you want about 6 cups of slices)
2 T olive oil
Recipe
Peel the onions and cut them into 1/4 inch slices. Place the onions in a slow cooker and drizzle the oil over the slices. Place the lid on the cooker and adjust the heat to high. Cook 8 to 10 hours, until the onions carmelize. They will then have a deep brown color.
Leftover onions can be refrigerated for up to 3 days or frozen for up to a month.