Step 1

Heat the butter and oil in a medium saucepan over medium heat. Add the chopped onions and sauté for about 10 minutes.

Step 2

Add the Worcestershire sauce, salt, black pepper, and cayenne pepper to the onions. Make sure the spices are well-mixed with the onions. Reduce the heat to medium-low and cook until onions are browned and caramelized.

Step 3

Set the onions aside and allow to cool.

Step 4

Place the cream cheese, sour cream, and mayonnaise in a large bowl and mix with an electric mixer until blended. Stir in the onions and combine well. Taste the dip and adjust the seasonings if needed.

Step 5

Refrigerate the dip for at least two hours to allow flavors to blend.

Step 6

Serve with chips or freshly cut vegetables.