In medium-size skillet, heat olive oil over medium heat. Add onion; sauté for 5 minutes. Stir in anchovy; cook 5 minutes. Add tomatoes, 3/4 teaspoon salt, 1/8 teaspoon black pepper, the oregano and red-pepper flakes; simmer, uncovered, for 10 minutes, stirring occasionally.
Heat oven to 350 degrees F. Grease a 13 x 9 x 2-inch baking dish. Season swordfish with the remaining salt and pepper. Place fish in the prepared baking dish. Spoon the tomato sauce over the swordfish.
Bake in 350 degree F oven for 15 minutes or until the fish flakes when touched with a fork. Garnish with the grated lemon rind. Makes 8 servings.