Steam cabbage leaves, covered, 3 minutes; set aside.
Heat oil in a large nonstick skillet over medium heat. Add leek, celery, carrot, and garlic; sauté 7 minutes. Add rice, 1 cup broth, and fennel seeds; cover and cook 7 minutes or until the liquid is nearly absorbed. Combine the rice mixture, 2 tablespoons parsley, and 1/2 teaspoon salt in a bowl; toss well, and set the rice mixture aside.
Add 1/3 cup broth to skillet; place over medium heat until hot. Add onion; cook 10 minutes, stirring occasionally. Add remaining 1/3 cup chicken broth, parsley, and next 5 ingredients (parsley through tomatoes); bring to a boil. Cover, reduce heat, and simmer 10 minutes. Remove from heat; stir in olives and pepper. Set sauce aside.
Preheat oven to 400°.
Spoon 1/3 cup rice mixture onto each cabbage leaf, and roll up jelly-roll fashion. Place cabbage rolls in a 13 x 9-inch baking dish coated with cooking spray. Spoon sauce over cabbage rolls. Cover and bake at 400° for 1 hour.