We scrub and debeard each closed mussel well under running cold water. We place the mussels in a large bowl. The mussels are rather dirty, so it takes us about 15 minutes to clean them.
We add the red pepper flakes to the garlic and oil, and raise the heat to medium. Next, we add one teaspoon of the parsley, the bay leaf, a little salt, some freshly ground black pepper, and the stock to the pot. We simmer and meld the flavors for a couple of minutes.
When the pasta water is boiling, we add some salt and the linguine.
While the pasta is cooking, we add the closed mussels, (any that are open and do not close when tapped against the bowl are discarded), to the garlic pot and cover. We cook over medium heat, shaking the pot occasionally, and cook for about 5 minutes until all the mussels have opened.
We remove the opened mussels to a serving dish (covering with foil to keep warm). We add ½ cup of the water in which the pasta is cooking to the sauce created by the cooked mussels, garlicky oil and stock. We lower the heat to low, discard the bay leaf, and wait for the pasta to be just al dente.
We add the drained cooked linguine to the sauce, stir well, add the rest of the parsley, and serve topped with the reserved mussels and additional red pepper flakes.