Preheat oven to 180°C fan-forced. Lightly grease a baking tray with higher sides with olive oil.
Arrange the potato slices in overlapping layers across the base. Drizzle with 1 tbsp olive oil, season with salt and pepper, and bake uncovered for 20 minutes until just tender.
Scatter the red onion, cherry tomatoes, olives, and garlic over the potatoes. Season lightly, drizzle with 1 tbsp olive oil, and bake for another 10 minutes.
Pat the fish fillets dry, then season with salt, pepper, and lemon zest. Place on top of the vegetables. Drizzle with the remaining olive oil and lemon juice, then splash over the wine. Scatter half the parsley and basil.
Bake for 12–15 minutes, or until the fish flakes easily with a fork.
Sprinkle with the remaining herbs and serve immediately with crusty bread and / or a salad.