Sprinkle the chicken with salt and pepper. Let stand for 15 minutes.

Preheat the oven to 325 F.

Heat half of the butter in a large Dutch oven over medium heat. When it has melted and is hot, add the chicken and brown on all sides. Be gentle when turning it, so as to avoid ripping the skin (2 large wooden spoons work well).

Remove the chicken to a large bowl. Add the chopped bacon to the pot and cook until crisp.

Add the onions to the pot with bacon along with a pinch of salt. Stir, cooking, until the onions are translucent.

Add the hard cider and rosemary. Mix, scraping up any bits stuck to the bottom of the pan. Add the potatoes and mix in. Add a few pinches of salt to taste as well as several turns of the pepper grinder. Place the chicken on top of the onions and potatoes. Bring to a boil, and then cover the pot with a heavy, fitted lid and place in the oven.

Roast for 1 1/2 hours, or until cooked through. When cooked through, the chicken, when pierced, will run with clear juices.

While the chicken is cooking, heat a skillet (nonstick or cast iron) over medium high heat. Add the remaining 1 1/2 tablespoons of butter. When it is melted, add the apples with some sugar to encourage browning and sweetness (use more sugar if you like it sweeter).

I prefer my apples to have the slightest bite of crispiness at their center when cooked, so I removed them from the heat as soon as they got some color on them. Cook them a bit longer though if you want them meltingly tender.

Remove the chicken from the oven when done. Carefully remove the whole chicken from the pot and place it on an oven safe dish or shallow bowl. Tent it with foil and place it in a warm oven (for my oven, I can just turn it off and it will retain the heat. If yours loses heat quickly then set it at 180 F).

Bring the "au jus" to a boil in the pot. Stir in the mustard. Then add some of the au jus to the cream to warm the cream up (this will prevent it from curdling in shock). Turn the heat down and stir the warmed cream-au jus mixture into the pot. Let the sauce simmer--but not boil vigorously--until it coats the back of a spoon. This will probably take about 5 minutes.

Taste for more salt or pepper. Mix the apples into the pot.

Serve joints of the chicken (if serving individually--you can also of course present the whole roasted chicken but we are not that fancy!) with potatoes and apples and the sauce.