Preheat oven to 425°F (220°C). In a small bowl, combine olives, capers and 1/2 tsp (2 mL) lemon zest (save any left over for a later use). Set aside.
Pat fish dry with paper towel, place on a parchment paper-lined baking sheet. Season with salt and pepper. Sprinkle with 1 tbsp (15 mL) lemon juice. Top each fillet with a quarter of the olive and caper mixture and grape tomatoes. Sprinkle with oregano. Drizzle with olive oil.
Roast for 8 to 12 min., or until fish is opaque and cooked through. Serve with rice or potatoes.
The combo of capers and olives elevates delicate cod with bold flavors. Juicy grape tomatoes roast to perfection in the same pan.