Place a large pot of water over high heat and bring up to a boil. Once boiling, add some salt and the egg noodles and cook until al dente according to package directions. Thoroughly drain and reserve.
In the meantime, place the turkey cutlets between two pieces of plastic wrap. Smack the cutlets a few times with a small heavy-bottomed skillet to make them a bit thinner, about 1/4-inch thick.
Place a large skillet over high heat with 2 turns of the pan of EVOO, about 2 tablespoons. Season turkey with a little salt, pepper and poultry seasoning, and brown them for 2-3 minutes on each side, working in batches to avoid overcrowding the pan. Chop the browned cutlets into bite-sized pieces and loosely cover them with aluminum foil to keep warm.
Once all of the turkey has been browned, add 2 tablespoons butter to the skillet. Once melted, add the shallots and cook for 2 minutes. Sprinkle the skillet with the flour and cook for 1 minute. Whisk in white wine, stock and sour cream. Bring up to a bubble and cook until nice and thick. Add the turkey and drained noodles back to the skillet and toss until the noodles are coated and the turkey is distributed.
In a small hot skillet melt the other 2 tablespoons of butter, then add the bread crumbs and get them nice and toasty. Mix in a couple of handfuls of Parmigiano Reggiano and give it a toss so the cheese melts a bit. Remove from heat and add the chopped parsley. Sprinkle the bread crumb mixture over the turkey and noodles. Serve each helping of tetrazzini with a little of the chopped cornichons on top.