In a large, deep pan over medium heat, warm half of the olive oil. Add the diced onion and sauté for 5–6 minutes until lightly golden and softened. Stir in the crushed garlic and cook for another 1–2 minutes, making sure it doesn’t brown.

Lower the heat, then incorporate the grated tomatoes, paprika, and chili flakes. Stir gently and let the mixture simmer for 2–3 minutes. Push the ingredients to the sides of the pan, creating space in the center.

In a separate pot, bring salted water to a rolling boil. Add the pasta and cook until al dente, about 10 minutes. Once cooked, drain and set aside, reserving a little pasta water if needed for loosening the sauce later.

Increase the heat under the sauce pan to medium. Add a drizzle of the remaining olive oil, then place the shrimp in the center with a pinch of salt and pepper. Sear the shrimp for about 3 minutes on each side, spooning a little of the tomato mixture over them as they cook. Once pink and opaque, remove them from the pan and cover with foil to keep warm.

Into the same pan, pour in half of the lemon juice, lemon zest, half the chopped parsley, the dry sherry, and a splash of water. Stir everything to combine with the sauce base.

Add the cleaned mussels and cover the pan with a lid. Allow them to steam for 5 minutes or until all the shells open. Discard any that remain closed.

Once the mussels are ready, return the shrimp to the pan. Add the cooked pasta and toss everything together, ensuring the sauce coats each strand evenly. If the mixture seems dry, drizzle in a bit more olive oil or a spoonful of reserved pasta water.

Plate the pasta with generous helpings of shrimp and mussels. Garnish with the remaining parsley and a lemon wedge on the side. Finish with a light drizzle of olive oil and a pinch of freshly cracked black pepper just before serving.