For the Chicken: Preheat the oven to 400^° F. Arrange a rack inside a roasting pan and set aside.

Season the chicken both inside and out with the kosher salt and black pepper.

In a small bowl, combine the honey, lemon zest, lemon juice and butter.

Place the chicken on the rack in the roasting pan breast side up and roast until lightly browned, about 30 minutes. Using a pastry brush, brush half of the honey-butter mixture over the chicken, and sprinkle with half the thyme. Return the chicken to the oven and continue to cook another 30 minutes, or until an instant-read thermometer inserted in the thickest part of the thigh registers 165^° F. Remove the chicken from the oven and brush with the remaining honey-butter blend and sprinkle with the remaining thyme.

Transfer the chiken to a platter or cutting board to rest for 10 minutes before carving.

To serve, spoon the sweet potatoes into the center of 4 large plates and arrange the chicken on top. Drizzle the chicken with any remaining pan juices and serve immediately.

For the Mashed Potatoes:  Preheat the oven to 400^° F.

Lightly prick the potatoes a few time with a fork and place the potatoes on a foil lined baking sheet, and drizzle with the vegetable oil.  Lightly sprinkle the potatoes with salt and pepper. Bake until knife tender, when the juices begin to bubble, about 1 hour and 15 minutes. Remove from the oven and set aside until cool enough to handle.

Cut the potatoes in half lengthwise and scoop out the flesh with a spoon into a large bowl. Add the cream,  brown sugar, butter, syrup, and salt and pepper to taste.  Add the thyme, if using, and mix, mashing until the potato mixture is smooth. Cover to keep warm until ready to serve.