Prepare the Filling:
In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the minced garlic and sauté for 1-2 minutes until fragrant. Add the chopped spinach and cook for 3-4 minutes, or until wilted. Remove from heat and let cool slightly. Once cooled, stir in the crumbled feta cheese, lemon juice, oregano, and fresh dill (if using). Season with salt and pepper to taste.

Prepare the Salmon:
Preheat the oven to 375°F (190°C). Place the salmon fillets on a cutting board, skin-side down. Use a sharp knife to carefully cut a slit along the side of each fillet, creating a pocket for the stuffing. Be careful not to cut all the way through.

Stuff the Salmon:
Spoon the spinach and feta mixture into the pocket of each salmon fillet. Press gently to ensure the filling is evenly distributed.

Cook the Salmon:
Heat 1 tablespoon of olive oil in an oven-safe skillet over medium-high heat. Once hot, add the stuffed salmon fillets, skin-side down, and cook for 2-3 minutes until the skin is crispy. Flip the fillets carefully and transfer the skillet to the preheated oven. Bake for 12-15 minutes, or until the salmon is cooked through and flakes easily with a fork.

Finish and Serve:
Optional: For extra richness, melt 1 tablespoon of butter in the skillet after removing the salmon from the oven, and drizzle over the top of the fillets. Serve with lemon wedges and a side of your favorite vegetables or salad.