Heat a large skillet over medium high heat. Season turkey with poultry seasoning, salt and pepper. Add 1 1/2 turns of the pan of oil, 1 1 /2 tablespoons. Brown 6 cutlets 2 minutes on each side, remove to a plate and repeat with remaining pieces of turkey. Add butter to the pan. When it melts, whisk in flour and cook a minute. Whisk in stock or broth and bring up to a bubble. Reduce heat to simmer and slide turkey back into pan to finish cooking in gravy.
To a second skillet over medium high heat, combine oil and butter. When butter melts into oil, add celery and onions and season with salt, pepper, poultry seasoning. Saute 5 minutes until just tender, add sage, parsley, prosciutto and stir to combine. Crumble muffins into the pan. Moisten stuffing with broth and heat through. Remove from heat. Cover with foil to keep warm.
Use an ice cream scoop to mound stuffing on plates and top with 2 cutlets and a small ladle of gravy.