Heat canola oil in large deep skillet or Dutch oven and brown the turkey breasts on both sides, starting skin side down. Cool turkey breasts, wrap and refrigerate to firm them back up.
Melt butter in the skillet or pot you browned the turkey in and add apple, celery and onion. Season with salt, pepper, bay and thyme; cook to tender 10 minutes or so. Add parsley and deglaze with calvados or brandy. Add sausage and turkey trimmings, and lightly brown, do not cook sausage until dry. Stir in stuffing, season with a little celery salt and moisten with stock, adding just enough to make bread damp but not wet. Stir in chestnuts. Cool stuffing completely.
Roll out 1 sheet of puff pastry on lightly floured surface. Top the pastry with half the stuffing blend leaving a border to work with. Place a browned breast skin side down on edge closest to you, wrap and roll the Wellington, trim and tuck the pastry and secure edges with a brush of water. Create any design you like or simply brush with egg wash. Repeat with remaining breast and chill at least 30 minutes.
Arrange rack at center oven and arrange the breasts on large, parchment-lined baking sheet with a few inches between them. Top with foil but do not seal, and bake at 375 degrees for 40 minutes. Remove foil and bake 20 minutes longer or until cooked though and deeply golden in color. Cool 20 minutes before slicing and serving.
Serve with homemade cranberry sauce (mix 1 cup water, 1 cup sugar, 1 12-ounce bag cranberries; boil until popped and sauce forms) and gravy (butter and flour to thicken turkey stock; add pepper and Worcestershire, optional tempered egg yolk) and steamed green beans alongside.