Two to four hours before you want to eat, remove the legs and wings from the chicken. If you wish separate the back from the breasts to make the chicken fit the pot better. Cover with the water, bring to a simmer and cook for thirty minutes.
Remove the breast from the pot, while the rest continues to simmer. When it's cool enough to handle, remove the breast meat and return the skin and the carcass to the pot. Chop or shred the breast meat into bite-sized pieces.
After one hour of cooking remove the legs from the pot and when they're cool enough to handle remove the meat from the bones and return the bones and skin to the pot. Cut the dark meat into bite-sized pieces.
While the bones continue to simmer, add four carrots to the pot. Peel and cut the remaining carrots into bite-sized pieces and hold them in a bowl of cold water covered with a paper towel.
Cut the leeks in two, to separate the green from the white and pale green parts. Cut the greens in half lengthwise and wash out any dirt. Add them to the pot along with the bay leaves and the bacon (if using). Simmer for at least another hour or up to three more hours.
Cut the leek whites into half inch discs. (If the leeks are very dirty you'll need to cut them in half lengthwise, clean them and cut them into half-inch pieces. Add them to the carrot mixture.
Strain the broth into a clean pot (or simply remove all bones, vegetables, and bay leaves from the broth).
Strain the carrot and leeks and add them to the broth and simmer for 10 minutes or until the carrots are al dente. Add the reserved chicken the cooked barley and the prunes and simmer until it's all piping hot. Taste for seasoning and add more salt as needed, along with freshly ground black pepper.