In a small pot over medium heat, combine the lemon juice and water and bring to a simmer.
2 tablespoons fresh lemon juice, 1 tablespoon water
Reduce the heat to low and whisk in the butter one tablespoon at a time. Allow it to melt before adding the next piece.
8 tablespoons unsalted butter
Add the garlic, Worcestershire, lemon zest, and pepper.
2 tablespoons Worcestershire sauce, 3 cloves fresh garlic, 1 tablespoon lemon zest, ½ teaspoon coarsely ground black pepper
Remove from the heat and whisk in the Dijon mustard until the mixture is smooth and creamy.
2 teaspoons Dijon mustard
Add in the parmesan cheese and chopped parsley.
1 tablespoon fresh parsley, 2 tablespoons grated Parmesan cheese
Taste for seasoning and add salt as desired.
Kosher salt