Base mix: In a very large bowl or blender, combine vinegar, lemon juice, mustard, sugar, garlic, onion powder, and all dried herbs. Whisk or blend until smooth.
Emulsify: Slowly whisk in oil until slightly thickened.
Add creaminess: Whisk in mayonnaise until fully combined and silky.
Finish: Stir in Parmesan cheese and water. Adjust salt/pepper to taste.
Rest (important): Refrigerate at least 2–4 hours (overnight is best) so flavors fully develop.