Soak your mussels in a bowl of cold water for at least 30 minutes. After, remove the beards from the mussels by carefully and gently removing it with your finger or cutting them with a sharp knife.

In a pot with a lid, add olive oil and heat over medium-high heat. Add your diced shallots and cook for about 5 minutes.

Add your diced garlic and then cook for another 2-3 minutes until the garlic is fragrant.

Add your wine, vinegar, salt, black pepper, and red pepper flakes and bring the sauce to a boil.

Once the sauce is boiling, reduce the heat to bring it to a simmer and add your mussels. Cover the pot with a lid and allow the mussels to cook for about 8-10 minutes, until they are all opened up. Shake the pot occasionally to move the mussels around.

Once the mussels are done cooking, remove them from the pot using a slotted spoon.

Add to the sauce, one stick of unsalted butter and your freshly chopped parsley. Allow the sauce to simmer for about 5-10 minutes, until the butter is fully melted and the sauce has slightly thickened. After, pour the sauce on top of the mussels.

Garnish with fresh parsley and serve with a toasted baguette.