Pat the salmon fillets dry and season both sides with salt and black pepper.
Heat the olive oil in a large skillet over medium-high heat. Place the salmon in the pan and cook for 4 to 5 minutes on each side until golden and cooked through. Remove the fillets to a plate and set aside.
Lower the heat to medium and add the garlic to the same skillet. Stir for 30 seconds until fragrant.
Add the halved cherry tomatoes and Italian seasoning. Cook for 2 to 3 minutes until the tomatoes begin to soften.
Pour in the heavy cream and stir in the Parmesan cheese. Simmer for 2 minutes until the sauce thickens slightly.
Add the baby spinach and stir until it wilts, about 1 minute.
Return the salmon to the skillet and spoon the sauce over the top. Garnish with fresh basil leaves before serving.