Preheat oven to 425℉
Prepare a baking sheet by lining it with parchment paper.
Brush skin side of salmon with 1 tablespoon of olive oil and place it on the prepared baking sheet.
Season salmon with 1⁄2 teaspoon salt, 1⁄4 teaspoon pepper, and red pepper flakes.
Bake salmon for 14-17 minutes or until salmon flakes apart with a fork. Bake time will depend on the thickness of your filets.
While salmon is baking, heat remaining tablespoon of oil in a medium skillet over medium heat.
Add onions and cook until they become transparent.
Add garlic and spinach. Cover and allow spinach to cook down. Stir occasionally.
Drain liquid off and return the skillet to the stove.
Add heavy whipping cream, 1 teaspoon salt, and 1⁄4 teaspoon pepper. Continue cooking until sauce thickens. Stir frequently.
Add cherry tomatoes. Cook for an additional 2 minutes.
Spoon mixture over top of baked salmon.
Top with strips of fresh spinach and serve.