Bring the water to a boil in a large pot. Add the mussels, and cover and cook over high heat until the mussels open (approximately 4-5 minutes).
Discard any mussels that do not open, and transfer opened mussels to a plate.
When cool enough to handle, loosen the meat slightly from one half of the shell and discard the empty half. Remove the beard – the little fibrous tuft that looks like seaweed – from the straight side of each mussel. Pour the wine from the pot over the mussels and set aside.
Combine the oil and the butter in a small skillet over medium heat. When the butter has melted, add the minced garlic and cook until tender.
Place the bread crumbs in a large bowl, then pour the melted butter mixture over the bread crumbs and Add in the grated lemon zest, red pepper flakes, chopped parsley, and salt and pepper. Toss to coat.
Top each mussel with the bread crumb mixture, then broil in a preheated broiler for 2-3 minutes.