Bring a large pot of salted water to a boil.
Add fettuccine and cook for 8 to 10 minutes or until al dente.
Boil, steam, or pan fry the salmon until cooked.
Break the cooked salmon into small pieces, set aside.
Heat the olive oil in a pan and saute the garlic and onion.
Add in the salmon pieces, spinach, and a bit white wine and let cook for 1 minute.
Stir in the cream, tomato concentrate, flour, spinach (optional), and Parmesan cheese.
Add salt and pepper to taste and let simmer for 3 minutes.(If it gets too dry, add in more cream or white wine).
When the sauce is ready, add in the pasta and toss until coated.(Or you can just pour the sauce over the pasta).