Step 1

Adjust oven rack to lower-middle position and heat oven to 325 degrees. Pat chicken dry with paper towels and sprinkle both sides with salt and pepper. Heat oil in 12-inch ovensafe skillet over medium heat until shimmering. Add chicken, skin side down, and cook, without moving it, until well browned, about 8 minutes. Using tongs, flip chicken and brown on second side, about 3 minutes. Transfer chicken to large plate.

Step 2

Pour off all but 2 tablespoons fat from skillet. Add chopped fennel and red pepper flakes and cook, stirring frequently, until fennel is lightly browned, 4 to 5 minutes. Add broth, orange juice, and Pernod; bring to simmer, scraping up any browned bits. Return chicken to skillet, skin side up (skin will be above surface of liquid). Transfer skillet to oven and bake, uncovered, until chicken registers 195 degrees, 35 to 40 minutes. Whisk water and cornstarch together in small bowl; set aside.

Step 3

Using tongs, transfer chicken to serving platter and tent with aluminum foil. Place skillet over high heat. Cook, occasionally scraping side of skillet to incorporate fond, until sauce is thickened and reduced to 1½ cups, 8 to 10 minutes. Adjust heat to medium-low. Whisk cornstarch mixture to recombine and then whisk into sauce and simmer until thickened, about 1 minute. Off heat, whisk in lemon juice, olives, and orange zest, and season with salt and pepper to taste. Pour sauce around chicken, top with fennel fronds, and serve.