For the rub: Combine the brown sugar, superfine sugar, salt, pepper and cayenne in a bowl and set aside for later use.
For the glaze: Mix the honey, lemon juice and chile sauce in a bowl, mix well and set aside for later use.
For the onions: Heat a large pan over medium heat. Add the butter and melt completely. Then add the sliced onions, salt and pepper. Cook, stirring regularly, until golden brown, 15 to 20 minutes. Remove from the heat and set aside to cool.
For the potatoes: Preheat the oven to 350 degrees F. Place the potatoes in a pot of cold water with 1 tablespoon salt. Bring the water to a boil, and reduce the heat to a low simmer until almost completely cooked but still slightly firm, 10 to 15 minutes. Drain the potatoes and cool.
Heat the olive oil in a saute pan over medium-high heat. Place the potatoes in the pan and brown on all sides taking care not to move the potatoes around too much, as it slows the browning process. Add 1/2 cup of the caramelized onions, the butter, rosemary, a pinch salt and some pepper. Toss to distribute the ingredients. Place in the oven for 5 to 10 minutes. Remove and keep warm for serving.
For the chicken: Rub the chicken halves liberally with 1/2 cup of the prepared brown sugar rub on both sides. Place the chicken in a non-reactive roasting pan and refrigerate for 1 hour.
Place the chicken in a skillet or roasting pan, skin-side up, taking care not to overlap the chicken. Roast in the oven until the chicken is brown and the skin is crispy, 40 minutes.
Baste with the lemon-honey glaze and place the skillet back in the oven until the glaze forms on chicken.
Serve the chicken with the caramelized onions and roasted potatoes.
Instead of roasting separately, the chicken can be placed on top of the potatoes halfway through the roasting process, which allows the juices to continually baste the potatoes adding extra flavor.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.