In a skillet over medium heat, add a drizzle of olive oil. Sauté the chopped spinach until wilted, about 2-3 minutes. Remove from heat and let cool slightly.
In a mixing bowl, combine the sautéed spinach, cream cheese, feta cheese, Parmesan cheese, dill, lemon juice, garlic powder, onion powder, salt, and pepper. Mix until well combined.
Take the salmon fillets and make an incision along the side of each fillet to create a pocket for stuffing.
Generously fill each salmon pocket with the spinach and cheese mixture, ensuring not to overfill.
In a small bowl, combine smoked paprika, cayenne pepper, and a pinch of salt. Rub this spice mixture all over the outside of the salmon fillets.
Heat olive oil in an oven-safe skillet over medium-high heat. Once hot, carefully place the stuffed salmon fillets in the skillet, searing for about 3-4 minutes on each side until golden brown.
Transfer the skillet to the preheated oven and bake for an additional 8-10 minutes, or until the salmon is cooked through and flakes easily with a fork.
Remove from the oven and let cool for a few moments before serving.
Notes
Serve on a bed of mixed greens with lemon vinaigrette and garnish with lemon wedges.