In a small bowl, combine the whole Red Peppercorns (1 teaspoon), Fennel Seeds (1 teaspoon), Ground Black Pepper (1 teaspoon), Kosher Salt (1 teaspoon), Fresh Rosemary (1 tablespoon), Fresh Thyme (1 tablespoon), Garlic (2 clove), and Brown Sugar (1 1/2 tablespoon).
Using a sharp knife, trim any excess fat from the Bone-in, Skin-on Chicken Thigh (1 pound). Pat chicken dry with a paper towel. Liberally sprinkle the rub onto both sides of the chicken, and press with your fingers so that it adheres.
Liberally sprinkle the rub onto both sides of the chicken, and press with your fingers so that it adheres.
Place chicken on a platter, and transfer to fridge to marinate for at least 2 hours and up to 8. Take chicken out of the fridge 15 minutes before cooking.
To grill, place thighs skin side down on the 375 degrees F (190 degrees C) grill for 6 minutes. Turn chicken, and continue cooking for approximately 12 minutes. For roasting, set a rack over a rimmed baking sheet. Place chicken on rack in the oven at 450 degrees F (230 degrees C). Roast 25-30 minutes, until skin is crispy and browned and flesh is cooked through, but still juicy.
Tent the chicken and let it rest for 5-7 minutes to redistribute the juices in the meat. Serve.