Pat the salmon fillets dry with paper towels and season both sides with salt, black pepper, and red chili flakes.
Heat the sun-dried tomato oil (or another type of oil, such as olive oil or avocado oil) in a large skillet set over medium-high heat. Once the skillet and oil are hot, add the salmon, leaving space between each fillet.
Cook the salmon for 3-4 minutes on each side, then remove the salmon to a clean plate. Use paper towels to wipe out any extra oil in the pan. Note: If you are cooking salmon fillets with the skin on, add them to the skillet skin-side-down first.
Return the skillet to medium heat. Melt the butter and cook the garlic for approximately 30 seconds or until fragrant.
Stir in the spinach and drained sun-dried tomatoes and cook for about one minute or until the spinach is slightly wilted.
Reduce the heat to low and stir in the heavy cream. Gently bring to a simmer, stirring often. If the sauce is too thick, add a little broth until the desired consistency is reached.
Remove from heat and stir in the freshly grated parmesan cheese until melted. Carefully nestle the cooked salmon fillets into the sauce and serve with fresh basil, parsley, lemon juice, or parmesan cheese, if desired.