Preheat oven to 200C/Fan180C
Place cod fillets in a large baking dish or on a parchment-lined baking sheet. Brush fish with approx. 1 Tbsp of olive oil, dividing evenly among fillets. Season with salt + pepper.
Place cod in the oven and bake for 15 minutes. If your cod is on the thinner side, you may choose to cook it about 12 minutes. The fish should be opaque and flake easily when done.
While the cod cooks, make the pesto by adding all pesto ingredients into a food processor. Blend until a paste forms, adjusting seasonings as desired.
Remove fish from oven. Serve + top each fillet with pesto. Finish with a squeeze of lemon juice overtop (if desired). Enjoy!
