Boil a large pot of salted water for the pasta, then cook it al dente according to package directions (or take it off the heat a minute or two before the package says). Start the sauce about 10 minutes before the pasta is ready.
Lightly season the salmon with Creole seasoning, salt, and pepper.
Heat the oil and butter in a skillet over medium-high heat, and cook the salmon for 2 minutes per side.
Take the fish out of the pan and set it aside. Reduce the heat to medium.
Add the sun-dried tomatoes, garlic, and Dijon mustard to the pan. Cook for 30 seconds, stirring constantly.
Add the cream, chicken stock, lemon juice, Cajun seasoning, salt, and pepper to the pan. Stir until the sauce is smooth.
Toss the drained pasta with the sauce and spinach. Cook it for about a minute to soak up the sauce, adding more stock if it's too thick.
Then add salmon and break it up or leave it as is, as desired. Adjust seasonings to taste.
Remove it from the heat. Serve with freshly grated parmesan cheese.