To prepare risotto, place farro in a large bowl; cover with water to 1 inch above farro. Let stand 30 minutes; drain.
Combine broth and cider in a large saucepan; bring to a simmer (do not boil). Keep warm over low heat.
Melt 2 tablespoons butter in a large saucepan over medium-high heat. Add fennel, and sauté for 5 minutes or until lightly browned and tender. Remove fennel from pan. Add farro, and cook for 3 minutes over medium heat, stirring constantly. Add wine, and cook for 5 minutes or until the liquid is nearly absorbed, stirring constantly. Add broth mixture, 1 cup at a time, stirring constantly until each portion is absorbed before adding the next (about 35 minutes total). Add up to 1 cup water as needed until farro is al dente. Stir in fennel, grated lemon rind, 1 teaspoon salt, 1 teaspoon pepper, and cinnamon. Remove from heat. Cover and keep warm.
To prepare duck, sprinkle duck with 1/2 teaspoon salt, thyme, and 1/4 teaspoon black pepper; rub with garlic. Heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat. Add 4 breast halves, and cook for 2 1/2 minutes or until browned. Turn breasts over, and cook over medium-low heat for 5 1/2 minutes or until desired degree of doneness. Repeat procedure with remaining 1 tablespoon olive oil and 4 breast halves. Serve duck with farro risotto.