Preheat your oven to 400°F (200°C).

Grease a 9x13-inch baking dish with about 2 tablespoons of olive oil.

Evenly arrange sliced tomatoes, onion, and bell pepper at the bottom of the greased dish.

Pat the white fish fillets dry and place them on top of the layered vegetables. Season with salt, pepper, oregano, and thyme.

Sprinkle the minced garlic evenly over the seasoned fish fillets.

Drizzle approximately 2 tablespoons of olive oil over the entire dish.

Layer the lemon slices over the top of the fish fillets.

Cover the baking dish tightly with aluminum foil and place it in the preheated oven. Bake for 20 minutes.

After 20 minutes, carefully remove the foil and return the dish to the oven. Bake for an additional 5-10 minutes until the fish flakes easily with a fork.

Let the dish rest for a few minutes, then sprinkle with fresh parsley if desired.