Here's What You'll Need
mussels, butter, shallot, garlic, fennel, salt, black pepper, dry white wine, sherry vinegar, tarragon, creme fraiche, chives, baguette
Melt unsalted butter in a large skillet over medium heat (no higher). Add minced shallot then cook for 3 minutes, stirring occasionally.
Raise heat to medium-high, then add minced garlic and sliced fennel. Season with salt and a black pepper. Cook 2-3 minutes, or until fennel has softened.
Increase temperature to high, then add dry white wine, sherry, and fresh tarragon. Bring to a boil, then reduce by half. This will take about 3 minutes.
Add mussels to the pot, give them a stir, then place lid on top. Cook for 5-7 minutes. When you remove the lid, discard any that remain tightly sealed, as these were dead before cooking.
Remove pan from heat, transfer mussels to a bowl, then add the remaining butter and crème fraîche. Swirl pan to emulsify into the sauce. Return mussels to the pot, garnish with chives and serve with baguette!