Cut zucchini in half lengthwise; scoop out pulp with spoon, creating boat. Reserve pulp.
Bring large skillet of water to simmering. Add zucchini boats; simmer, uncovered, 3 minutes or until just tender. Remove zucchini with slotted spoon; cool under running cold water. Drain on paper toweling.
Empty skillet. Dry with paper toweling. Heat oil in skillet. Add beef; cook, breaking up clumps with a wooden spoon, for 5 minutes or until no longer pink. Add garlic, onion and sweet red pepper; cook 5 minutes. Add chili powder, zucchini pulp, tomato sauce, Worcestershire sauce and salt; cook for 10 minutes. Remove mixture from heat. Stir in half of the cheese.
Place the zucchini boats in a baking pan just large enough to hold them. Spoon the beef mixture into the boats. Top with the remaining mozzarella cheese.
Bake at 350 degrees F for 5 to 10 minutes or until cheese melts. Place one endive leaf in middle of each boat for sail, and serve with hot cooked noodles if you wish. Makes 8 boats.