01 - Preheat the oven to 400°F. Line a baking tray with parchment paper.
02 - Place salmon fillets evenly on the prepared tray. Season with salt and black pepper.
03 - Spread 1 tablespoon of basil pesto evenly over each salmon fillet.
04 - Distribute halved cherry tomatoes and red onion slices (if using) around the salmon. Drizzle olive oil over all ingredients.
05 - Bake for 15 to 18 minutes until salmon flakes easily with a fork and tomatoes are soft and blistered.
06 - Serve hot, garnished with fresh basil leaves and lemon wedges.