Preheat the oven to 425°F. Pat the fish dry and season well on both sides with kosher salt and black pepper. Prepare a baking dish and brush the bottom with the olive oil.
Arrange some of the pepper and onion slices on the bottom of the baking dish. Arrange the fish on top of the sliced vegetables.
In a small mixing bowl, combine the chicken broth, harissa paste, juice 1 lemon half, garlic, oregano, and spices. Whisk well. Pour the harissa and broth sauce all over the fish. Top with the remaining vegetable slices.
Cover the baking dish with aluminum foil and bake on the center rack of the heated oven for about 10 to 15 minutes or until the fish is cooked through and flakes easily when you poke it with a fork. (If you like, you can stick the fish back in the oven under the broiler, uncovered, very briefly to help it gain some color, but be careful not to over-cook your fish).
To serve, squeeze the remaining lemon half all over the fish and garnish with parsley. Serve immediately over brown rice, orzo, or your favorite grain!
This nutritional information refers to each serving of the entire recipe and not just the products used as ingredients.