1. Heat oil in large skillet over high heat. Add onions and 1/4 teaspoon salt; cook, stirring frequently, until the onions begin to brown, about 5 minutes. Reduce the heat to low, add 2 tablespoons water, and cover. Cook, stirring frequently, always covering the pan again, until the onions are reduced and have a deep caramel color, 25-30 minutes.