Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
Place the baby new potatoes in a pot of salted water, bring to a boil, and cook for 10-12 minutes until fork-tender, then drain and halve them.
Pat the cod fillet dry with a paper towel and place it on the prepared baking sheet.
Drizzle the cod with half of the extra virgin olive oil and season evenly with sea salt, black pepper, fresh thyme, and chopped parsley.
Arrange the halved baby potatoes and cherry tomatoes around the cod on the baking sheet.
Roast in the oven for 12-15 minutes until the cod is opaque and flakes easily with a fork.
While the fish roasts, whisk the remaining olive oil with the lemon juice in a large bowl.
Add the rocket, capers, and sliced black olives to the bowl and toss gently to coat.
Serve the roasted cod and warm potatoes over the fresh rocket salad for a clean, Mediterranean-inspired meal.