Mix Marinade: In a large mixing bowl, combine Pernod, olive oil, orange juice, lemon juice, grainy mustard, brown sugar, minced garlic, salt, and black pepper. Whisk until well blended and fragrant.

Prepare Chicken: Pat-dry the chicken thighs thoroughly with paper towels.

Marinate Chicken: Add the chicken thighs, fennel wedges, orange slices, fresh thyme, and fennel seeds to the marinade. Stir gently to coat everything evenly. Cover with plastic wrap and refrigerate for at least 2 hours or overnight.

Preheat Oven: Set your oven to 475°F (245°C).

Arrange Chicken: Place the marinated chicken thighs skin side up in a large ovenproof glass pan.

Add Veggies: Scatter the fennel wedges and orange slices around the chicken thighs.

Roast Chicken: Pour the marinade juices over the chicken and vegetables. Roast for 40-45 minutes, until the chicken is fully cooked.

Keep Warm: Transfer the chicken, fennel, and oranges to a serving plate and cover with aluminum foil.

Make Sauce: Strain the pan juices into a saucepan. Bring to a boil, then reduce heat and simmer until reduced to about 1/3 cup.

Serve: Arrange the chicken on the plate, garnishing with roasted fennel and orange slices. Drizzle the sauce over the chicken.