Step 1: Prepare the Linguine

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

Step 2: Prepare the Clam Sauce

1. Heat the olive oil and butter: In a large skillet or sauté pan, heat the olive oil and butter over medium heat until melted and shimmering.
2. Cook the aromatics: Add the minced garlic, chopped shallot, and red pepper flakes (if using). Sauté for 1-2 minutes, stirring frequently, until fragrant but not browned.
3. Deglaze with white wine: Pour in the white wine (or vegetable broth) and increase the heat to medium-high. Simmer for 2-3 minutes, allowing the alcohol to cook off and the liquid to reduce slightly.
4. Add clam juice: Stir in the clam juice, mixing well to combine the flavors.

Step 3: Cook the Clams

1. Add fresh clams: If using fresh clams, add them to the skillet. Cover with a lid and cook for 5-7 minutes, or until the clams open. Discard any clams that do not open.
2. Add canned clams (if using): If using canned clams, stir them into the sauce after simmering the clam juice, as they only need to be warmed through (about 2 minutes).
3. Season the sauce: Add salt, black pepper, lemon zest, and lemon juice to the sauce. Stir to combine and adjust the seasoning to taste.

Step 4: Combine Pasta and Sauce

1. Toss the linguine: Add the cooked linguine to the skillet with the clam sauce. Toss the pasta gently to coat it in the sauce, adding a splash of reserved pasta water if needed to loosen the sauce.
2. Finish with parsley: Sprinkle the chopped parsley over the pasta and toss again to combine.

Step 5: Serve

1. Plate the pasta: Divide the linguine with clam sauce among serving bowls, making sure to include clams in each portion.
2. Garnish: Garnish with extra parsley, lemon wedges, and grated parmesan cheese if desired. Serve immediately.