Preheat oven to 240ºC. Let the chicken sit out of the fridge for 30 minutes before cooking.
Begin by oiling a baking dish and then covering with the carrot, celery, onion and garlic.
To prepare the chicken, pat the skin dry with kitchen towel. Stuff the cavity of the chicken with the bouquet garni and lemon, then cross its legs at the knuckles and tie firmly with kitchen string. Rub olive oil, salt and pepper thoroughly over the entire surface of the skin, then place it on top of the vegetables and aromatics. Reduce the temperature to 190ºC and roast for 1 ½ hours. Remove the chicken from the oven, scatter the persimmons around the chicken and return to the oven for a further 30 minutes. Transfer the chicken and persimmons onto a serving dish.
To make the gravy, scrape all the contents of the baking dish including any crispy, burnt bits, into a colander, collecting the baking juices in a medium saucepan. Discard the vegetables but you might want to keep the soft, sweet flesh of a few of the garlic cloves to mix into the gravy. Remove ¼ cup of the gravy liquid and mix with 2 tsp of plain flour. Return to the saucepan with the white wine, mix and bring to the boil. Reduce the heat and simmer until thickened. Transfer to a gravy boat ready for serving.
To make the lentils, heat the butter in a small saucepan over medium heat, until foaming. Add the eschallots and bacon and cook until the eschallots are soft. Add the lentils and sauté for a few seconds before adding the stock or water and cook until tender. Remove from heat and stir in the parsley, lemon, salt and pepper to taste. Cover and remove from heat until ready to serve.
Note: Instead of roasting the persimmons, you could dice 2 peeled persimmons and fold through the lentil mixture at the same time as the parsley