~ Insert the slicing disc, adjusted to 3mm, into the large work bowl of the Cuisinart, and slice the onions. ~ Place a large skillet over medium-low heat and add the butter. ~ Once the butter is melted, add the onions with salt and pepper to the skillet and cook over low heat for about 1 hour, until onions are completely soft and caramel in color. The flavor of the Caramelized Onions is well worth the time it takes to prepare them.