Whisk mayonnaise, vinegar, lemon juice, and Dijon in a medium bowl until smooth.
Slowly stream in olive oil while whisking to create a creamy emulsion.
Stir in Parmesan, sugar, garlic powder, onion powder, Italian seasoning, parsley, salt, black pepper, and red pepper flakes.
Whisk in water a little at a time until the dressing is pourable.
Taste and adjust seasoning. Cover and chill 30 minutes for flavors to meld before serving.
Notes
Try a tablespoon of brine from pepperoncini or green olives for extra tangy depth. For a lighter version, swap half the mayonnaise for plain Greek yogurt. Store in a sealed jar in the fridge for up to 1 week; shake before using as it may separate.This recipe is an original creation inspired by classic Olive Garden Salad Dressing Recipe flavors. All ingredient ratios and instructions are independently developed.