Preheat the oven to 375 F spray an oven-safe cooking dish with oil. Using a paper towel, dab the oil from a 1/3 cup sun-dried tomatoes, before chopping. Add 1 tbsp olive oil and chopped sun-dried tomatoes to a skillet over medium heat. Cook for 1 minute, stirring until fragrant. Add 3 c. baby spinach and 1 c. chopped basil leaves to the skillet. Stir occasionally until wilted, about 3 minutes. Remove the skillet from the heat. Add 1/2 c feta cheese crumbled and stir until well combined with the other ingredients. Using a sharp knife, carefully slice the salmon through the center, just until the knife almost reaches the other side. Use a spoon to distribute the stuffing into the centers of each of the salmon fillets. Carefully transfer the salmon fillets to the prepared baking dish. Sprinkle with salt and pepper. Bake salmon on the center rack of the oven for 20 to 30 minutes or until cooked through.