Place the cod on a lightly oiled baking sheet, or one that has been sprayed with nonstick cooking spray. Drizzle 2 tablespoons of the olive oil over the fish and use your fingers to spread it over the top and sides. Sprinkle with salt and pepper. Roast for about 10 minutes, until the fish is just cooked through.
Transfer to individual plates and sprinkle with a bit of lemon zest, if desired. Spoon a bit of the herb dip on top and serve.