In a large pot, bring salted water to a boil and cook the fettuccine according to package instructions. Drain and set aside.
While the pasta cooks, heat olive oil in a large skillet over medium heat. Season the salmon fillets with salt and pepper, then add them to the skillet. Cook for about 4-5 minutes on each side, or until cooked through and flaky. Remove from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant. Add the chopped spinach and cook until wilted, about 2-3 minutes.
Pour in the heavy cream and bring to a gentle simmer. Stir in the grated Parmesan cheese, lemon juice, and dried Italian herbs. Cook for another 2-3 minutes until the sauce thickens slightly.
Flake the cooked salmon into large pieces and gently fold it into the creamy sauce. Add the cooked fettuccine and toss to combine, ensuring the pasta is well coated with the sauce.
Serve immediately, garnished with fresh parsley.