Pat the salmon dry with a kitchen towel, then season them with salt and black pepper.
Heat the oil in a large frying pan over medium heat, add the salmon (skin side up), cook for 3-4 minutes until golden brown, flip it on the other side, and cook for 2-3 minutes more. Transfer them to a plate.
In the same pan, add butter to melt, add the garlic and tomatoes and cook for 1-2 minutes. Then add the spinach and cook for 2-3 more minutes or until wilted.
Stir in Parmesan cheese, heavy cream, and fresh basil, then simmer for 5-8 minutes.
Add the salmon bake to the pan, cover it with the sauce and simmer for 2 to 3 minutes. Garnish with chopped basil and serve.
Notes
Salmon cooks quickly, so watch it closely and don't overcook it.