01 - Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it.
02 - Pat salmon fillets dry with paper towels. Brush both sides with olive oil, then season with salt and pepper. Place fillets skin-side down on the prepared baking sheet.
03 - In a food processor, combine basil leaves, pine nuts or walnuts, Parmesan cheese, garlic, olive oil, lemon juice, and salt. Blend until smooth, scraping down the sides as needed.
04 - Spread 1 to 2 tablespoons of pesto evenly over each salmon fillet.
05 - Bake in the preheated oven for 15 to 18 minutes, or until the salmon flakes easily with a fork and is cooked through.
06 - Serve hot, garnished with lemon wedges and fresh basil leaves if desired.