4 to 6 boneless, skinless chicken thighs (1–1/4 to 1–1/2 lbs)
Salt and freshly ground black pepper
4 tablespoons olive oil, divided
4 to 6 thin slices of navel orange, peeled
2 medium fennel bulbs
1/2 medium yellow onion, thinly sliced
1 clove garlic, minced
3 tablespoons orange juice
2 teaspoons grated orange zest (about 1/2 orange)
2 teaspoons honey
Preheat the oven to 400 °F, line a rimmed baking sheet with foil and coat with nonstick spray.
Trim any excess fat from the chicken thighs and season both sides with salt and pepper.
Form the thighs into their original “bone-in” shape and arrange them on the prepared baking sheet. Brush with 1 tablespoon olive oil and set aside.
Roast the chicken for 15 minutes, then remove from the oven and place an orange slice on top of each thigh. Continue roasting for 5 to 10 minutes or until the chicken reaches an internal temperature of 165°F.
While the chicken roasts, remove and discard the stalks from the fennel bulbs, reserving the fronds for garnish. Cut the fennel bulbs into thin slices, separating the rings as you would with an onion. Chop the fronds and set them aside.
Heat the remaining olive oil in a large frying pan over medium heat. Add the fennel and onion, season with salt and pepper and sauté until the mixture is nicely caramelized, 7 to 8 minutes.
Add the garlic and continue cooking, stirring often, 2 minutes longer. Stir in the orange juice, orange zest and honey. Continue cooking just long enough for the liquid to evaporate. Taste and adjust the seasoning if needed.
To serve, transfer the caramelized fennel to a serving platter, top with the chicken thighs and sprinkle with the fennel fronds.