Place a sauté pan over a medium-high heat, and melt about two tablespoons of butter in it. Once the butter is melted, add the onion slices to the pan and stir every couple of minutes. Season the onions with salt and fresh-cracked black pepper, remembering to stir often. Continue to cook over the medium-high heat, stirring often for about 15 to 20 minutes, or until the onions are brown and appear sticky. If the onions seem to be burning, lower the heat slightly, and continue to stir them. Remember that the volume of the onions will reduce to less than half of their original volume.