Preheat the oven to 400°F (200°C).
Place the cherry tomatoes in an oven-safe dish. Top with the sliced garlic and drizzle with half the amount of olive oil.
Place the dish in the oven, then immediately reduce the temperature to 350°F (180°C). Roast for 15 minutes.
After 15 minutes, remove the dish from the oven and place the fish on top of the tomatoes. Season everything with salt and ground black pepper, and drizzle the remaining olive oil over the fish.
Scatter the olive , thyme leaves, and chili flakes over the fish. Roast for a further 12-15 minutes until the fish is just cooked through.
Remove the dish from the oven and divide the fish, tomatoes, olive and herbs between the plates.
Stir the lemon juice into the remaining juices in the oven dish and drizzle it over the fish. Finish by sprinkling freshly grated lemon zest over the plates.