
Cook pasta until al dente according to the package instructions in a large pot of salted water.
Meanwhile, sauté the onion in butter in a large skillet over medium heat for 4-5 minutes.
Add the salmon and keep cooking for another 5-7 minutes, breaking it into flakes as it cooks.
Add the spinach and cook it for 1-2 minutes, until wilted.
Add the heavy cream, Parmesan, garlic, salt and black pepper. Stir and bring to a gentle simmer. You can also add a ¼ tsp. of red pepper flakes for a touch of heat if desired.
Add the cooked pasta and chopped parsley. Mix everything thoroughly. Garnish with parsley and grated Parmesan. Serve.