Gather all the ingredients before starting the recipe.
Pre heat oven to 425°F
Drizzle oil on the bottom of an oven proof casserole dish.
Add halved tomatoes, sliced red onion, drained capers, smashed garlic, juice and rind of 1/2 of a lemon and half of the chopped parsley. Season with kosher salt and freshly ground pepper. Toss to combine well.
Season fish with kosher salt, black pepper, oregano on both sides. Drizzle each side with remaining olive oil. Place seasoned fish on top of the vegetables, squeeze the juice of the other half lemon on the fish, add the lemon rind and 1/4 cup of chicken broth.
Place the baking pan, uncovered, in a pre heated oven and bake for 15-20 minutes.
Sprinkle dish with Kalamata olives and chopped parsley.
Serve with some of the tomato, onion and olives and some of the pan juices over each slice of fish,