In a bowl, combine Pernod, olive oil, orange juice, lemon juice, grain mustard, brown sugar, salt, pepper, thyme, and fennel seeds. Place fennel and chicken thighs in a large bowl and cover with marinade. Place clementines on top. Cover with plastic and marinade for a minimum of 4 hours but up to overnight.
Preheat oven to 475.
Place contents of bowl in a baking dish, with clementines on top. Roast for 35 minutes or until chicken is browned.
Remove from oven and transfer fennel, chicken, and clementines to a serving dish. Pour remaining liquid from baking dish into a pan and reduce for 8-10 minutes, until it is nice and syrupy.
Pour over chicken and serve immediately.
Recipe by Things I Made Today at https://www.thingsimadetoday.com/2013/10/08/roasted-chicken-thighs-clementines/