Try to make this at least a couple of hours ahead of your holiday party so the flavors have time to mingle. If necessary, thin with a little milk to proper dip consistency.
Using an electric mixer, beat the cream cheese until light and fluffy, about 1 minute.
Blend in the sour cream, then stir in the parsley, onion, garlic, and mustard. Add the lemon juice, basil, paprika, cayenne, and Parmesan cheese; stir.
Stir in 1 teaspoon of the Worcestershire sauce. Taste, then decide if you want to add more. Add salt to taste. Assess the texture: If necessary, thin it by whisking in milk a teaspoon or so at a time. Cover and refrigerate until serving.
Serve the dip in a hollowed-out loaf of bread, with dipping vegetables and crackers arranged in a star. Makes 3 1/2 cups of dip.