Cook the onions for 5-7 minutes, stirring often until they turn translucent. Add ½ teaspoon of salt, black pepper, nutmeg, thyme leaves, Worcestershire Sauce(optional) Then reduce the heat to medium-low. Continue to cook, stirring every 5-10 minutes, until the onions reach your desired level of caramelization. Deeply caramelized onions can take an additional 30-40 minutes.