Creamed Spinach-Stuffed Salmon

Preheat oven to 425 degrees F. Line a large rimmed baking sheet with parchment paper.

Heat oil in a large skillet over medium-high heat. Add shallots and garlic; cook, stirring often, until softened, about 2 minutes. Stir in crushed red pepper; cook, stirring constantly, for 30 seconds. Add spinach in batches; cook, stirring until wilted before adding more, about 3 minutes total. Remove from heat. Add mozzarella and cream cheese; stir until the cheeses melt. Let cool for 10 minutes.

Place salmon fillets skin-side down on a clean work surface. With a sharp knife, make a cut lengthwise down the middle of each fillet, cutting to but not through the skin. Transfer the salmon to the prepared baking sheet. Sprinkle evenly with salt and pepper. Fill each pocket with about 1/3 cup of the spinach mixture. Bake until the salmon is opaque in the center, 8 to 10 minutes.