Step 1: Prepare the Mussels

1. Clean the mussels: Scrub the mussels under cold running water to remove any dirt or sand. Use a small knife or your fingers to pull away the “beard” (the stringy fibers sticking out of the shell). Discard any mussels with broken shells or those that don’t close when tapped.
2. Cook the mussels: Heat 1 tablespoon of olive oil in a large skillet or pot over medium heat. Add the minced garlic, chopped shallot, and red pepper flakes (if using). Sauté for 1-2 minutes until fragrant.
3. Steam the mussels: Add the white wine (or vegetable broth) to the skillet and bring it to a simmer. Add the mussels, cover the skillet, and cook for 5-7 minutes, or until the mussels open. Discard any mussels that remain closed. Remove the mussels from the skillet and set aside, leaving the liquid in the skillet.

Step 2: Cook the Spaghetti

1. Boil the pasta: Bring a large pot of salted water to a boil. Add the spaghetti and cook according to the package instructions, until al dente. Reserve ½ cup of the pasta water before draining the spaghetti. Set the pasta aside.

Step 3: Make the Creamy Garlic Sauce

1. Sauté the garlic: In the same skillet with the mussel cooking liquid, heat 1 tablespoon of olive oil and 2 tablespoons of butter over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant.
2. Add the cream: Pour in the heavy cream and stir to combine. Let the sauce simmer for 3-4 minutes to thicken slightly.
3. Incorporate parmesan: Stir in the grated parmesan cheese, lemon zest, and lemon juice. Mix until the cheese is melted and the sauce is smooth.
4. Season the sauce: Add salt and black pepper to taste. Adjust the seasoning as needed.

Step 4: Combine Pasta, Sauce, and Mussels

1. Toss the pasta: Add the cooked spaghetti to the skillet with the creamy garlic sauce. Toss gently to coat the pasta in the sauce. Add a splash of reserved pasta water if the sauce is too thick.
2. Add the mussels: Return the cooked mussels to the skillet, tossing them gently with the pasta and sauce to combine.
3. Finish with parsley: Sprinkle the chopped parsley over the pasta and mussels, and toss again to distribute evenly.

Step 5: Serve

1. Plate the pasta: Divide the creamy garlic mussels and spaghetti among serving bowls, making sure to include mussels in each portion.
2. Garnish: Garnish with extra parsley, lemon wedges, and grated parmesan cheese if desired. Serve immediately with crusty bread for dipping into the sauce.