For the stuffing: Preheat the oven to 375 degrees F. Melt the butter in a small pan or microwave oven. Toss the bread with the melted butter and season liberally with some poultry seasoning. Arrange the bread on a baking sheet and bake until golden and toasty, 15 to 20 minutes.
In a large deep skillet heat the oil, half a turn of the pan, over medium-high heat. Add the bacon and cook to render the fat and until almost crisp. Add the apples, celery, onions, thyme, parsley and some salt and pepper. Cook to tender-crisp, 8 to 10 minutes. Add the toasted bread to the pan and moisten with some stock.
For the cranberries: Place the cranberries, 1 cup of water and the sugar in a pot. Bring to a boil. Cook to crack the cranberries and thicken, then remove from the heat.
For the gravy: Melt the butter in a medium saucepan over medium to medium-high heat, whisk in the flour and cook to light golden, 2 to 3 minutes. Whisk in the stock, and then add the syrup, Worcestershire and some pepper. Cook at a low bubble, stirring occasionally, until the gravy coats the back of a spoon.
For the casserole: Grease a casserole dish and fill with the stuffing. Top the stuffing with the cranberry sauce, spreading in an even layer. Shingle the sliced turkey across the cranberry sauce and top the turkey with some gravy, reserving some gravy to pass at the table.
Top the turkey with the cheese, then cool and store the casserole for a make-ahead meal or bake to serve immediately.
To bake and serve, preheat the oven to 375 degrees F. Bake the casserole from room temperature until hot through, light brown and bubbly, 35 to 45 minutes.
Place the buttermilk, Sriracha, salt, peppercorns, garlic, lemon, chives, dill and parsley in a double-bagged 2 1/2-gallon plastic resealable bag. Add the turkey breasts and refrigerate on the bottom shelf of the fridge overnight.
Preheat the oven to 325 degrees F.
Arrange a metal rack over or in a rimmed baking sheet and rub the rack with oil. Remove the turkey breasts from the brine and pat them dry. Arrange the breasts on the prepared baking rack and coat the skin with a little oil, sprinkle with poultry seasoning and cook until a thermometer reads 165 degrees F and the skin is light to medium golden brown, 45 minutes to 1 hour.