Season both sides of the salmon fillets generously with salt and pepper to enhance flavor.
Heat the olive oil in a large skillet over medium-high heat until shimmering, then carefully place the salmon fillets skin-side down. Sear the fillets for about 4-5 minutes on each side, or until they reach your desired doneness (the fish should be opaque and flake easily with a fork). Once cooked, remove the salmon from the skillet and set aside on a platter.
In the same skillet, lower the heat slightly and add the minced garlic. Sauté for approximately 1 minute or until fragrant—be careful not to burn the garlic as it can turn bitter.
Add the halved cherry tomatoes to the skillet and cook for 2-3 minutes, stirring occasionally, until they start to soften and release their juices.
Incorporate the fresh spinach, stirring until just wilted, which should take about 1 minute.
Gradually pour in the heavy cream, mixing thoroughly. Sprinkle in the grated Parmesan cheese and continue to stir until the cheese is fully melted and the sauce begins to thicken, around 3-4 minutes.
Stir in the Italian seasoning and taste the sauce. Adjust salt and pepper as needed for your personal preference.
Gently return the salmon fillets to the skillet, spooning the creamy sauce over each piece. Allow the salmon to simmer in the sauce for a couple of minutes to ensure it is warmed through.
Serve immediately while hot, adorned with fresh basil leaves for a burst of color and flavor.
Notes
Serve with crusty bread or over pasta for a complete meal.