Place the lemon juice egg yolk, mustard, anchovy paste, garlic, vinegar, and Worcestershire sauce in a blender and puree on lowest speed for a few seconds to blend.With the blender top on and the center top removed, slowly stream the oil into the blender until dressing is creamy and emulsified. Increase the speed as you go. Add the Parmesan and puree until creamy. If the dressing gets too thick, add either a little more lemon juice or warm water to make it the consistency you prefer. Taste and adjust the salt and pepper if desired.