Begin by rinsing your fresh mussels under cold running water, using a brush to scrub off any dirt and debris. Make sure to pull off the beards and discard any mussels that are cracked or remain open after a light tap.

In a large pot, place the cleaned mussels and add ¼ cup of water. Cover the pot and bring it to a gentle simmer over medium heat for about 3-4 minutes. Remove mussels from heat and discard any that haven’t opened.

In a mixing bowl, combine the softened unsalted butter with minced garlic, grated Parmesan cheese, chopped fresh parsley, and lemon zest. Season with salt and pepper, stirring everything together until creamy.

Carefully remove the opened mussels from their shells, discarding the empty halves. Place the mussels back on a baking sheet in their remaining half shells.

Spoon a generous amount of the prepared garlic butter mixture over each mussel. Preheat your broiler to high, then broil for about 2-4 minutes until the tops are golden and bubbly.

Garnish with additional chopped parsley and serve immediately with slices of crusty bread.