Heat the rest of the olive oil in a medium-size saucepan over medium-high heat. Add the remaining garlic, the leek, celery, onion, fresh fennel, and fennel seed and cook, stirring, until the vegetables begin to soften, 3 to 5 minutes. Add the tomatoes and the broth, season with salt to taste, and bring the liquid to a boil. Reduce the heat to low, partially cover the pot and cook 15 minutes. Add the fish and cook 5 to 10 minutes longer or until the fish flakes easily with a fork. Strain the fish and vegetables from the broth, cover to keep warm, and set aside. Reserve the broth (you should have 4 to 5 cups, 946 to 1180ml) and combine with the other broth to yield 6 cups (1.4L).