Not your everyday roast chicken. The mustard and coriander add body and depth to your meat, making it the perfect complement to a full-bodied red wine. Not your average pairing for not your average chicken!
Place coriander seeds in small frying pan, over medium low heat. Toast the seeds, shaking the pan as needed, for 2-3 minutes until the seeds are golden and very fragrant. Place the seeds in a mortar and pestle and grind seeds to form a course mixture. Add the ground seeds to a small bowl, along with both mustards and the juice and zest of one orange. Mix well to form a creamy thick sauce.
Pat chicken dry with paper towel and place in a large resealable bag such as a Ziplock. Add in the mustard, orange coriander mixture to the bag and close tightly. Rubbing the outside of the bag, coat the chicken in the mixture. Place in the fridge for 3 hours or up to overnight. Remove the chicken from the fridge 30 minutes prior to cooking so it can come to room temperature. Remove from the bag and place chicken in roasting pan leaving 1-2 inches of space around the pan.
Preheat oven to 425 degrees F.
Slice the onion and remaining oranges into 4-6 wedges each, and slice the top off the heads of garlic, keeping skin and cloves in tact. Place 2 onion wedges and 4 orange wedges inside the cavity of the chicken. Arrange the remaining wedges and garlic heads around the outside of the bird.
Drizzle the chicken with half of the olive oil and rub it all over, rubbing the marinade further and season the chicken with salt and pepper to taste. Then drizzle the remaining olive oil over the heads of garlic so it seeps in. Pour the orange juice into the pan but not over the chicken.
Roast, covered in the oven for 35 minutes, then uncovered for an additional 20 until the internal temperature reaches 170 degrees F and the skin is golden brown. Remove from the oven and let rest for 5 minutes before carving and serving, with pan juices on the side.
Leftovers will keep in an airtight container in the fridge for up to 3 days.