Fill a large pot with water, add a pinch of salt, and bring it to a boil. Cook spaghetti al dente according to package instructions, about 8-10 minutes, until tender yet slightly firm.

While the pasta cooks, season fresh salmon fillets with onion powder, salt, and pepper. Heat a skillet with olive oil and butter over medium-high heat. Cook the salmon for 2-3 minutes on each side until golden brown and flaky. Set aside.

In the same skillet, reduce the heat to medium. Sprinkle in the flour and whisk continuously for about 30 seconds until the paste turns a light golden color.

Pour in the minced garlic and wine or broth, allowing it to bubble for about a minute. Gradually whisk in the cream and lemon juice until the sauce is smooth.

Stir freshly grated Parmesan cheese into the sauce until melted. Return the salmon to the skillet, breaking it into bite-sized pieces.

Once the pasta is cooked, drain it and add it directly into the skillet with the sauce. Toss gently, adding reserved pasta water if needed.

Plate the salmon pasta immediately, garnishing with chopped parsley and additional Parmesan cheese.