The seductive aroma of onions cooking all day perfumes every corner of my house, yet I'm not lifting a finger. No standing at the stove with a wooden spoon, no turning the flame down, down, down to make sure nothing is burning. Caramelizing brings out the natural sugar in onions, resulting in a condiment you can use in everything from soup to scrambled eggs, in a panini or on top of pizza. If you've ever wondered how to make caramelized onions in the slow cooker, or whether it's even possible, I'm here to tell you that you can, and you must, because nothing could be easier. Use regular yellow onions, not Vidalia or other sweet onions that contain more water. I trim five pounds ($1.99) of ordinary yellow onions down to a bit less than four pounds, slice them in the food processor, and cook them for 9 hours. I've been putting caramelized onions in everything lately, and I'll share a couple of the ways I use them later this week. A batch of onions will keep in the refrigerator for a few weeks. You won't be able to resist their allure.