Heat a large sauce pot over medium high heat. Add butter, shallots, garlic and mushrooms and cook for 5 minutes. Add chicken stock, Worcestershire and tarragon. Combine cornstarch with water and make a paste. Whisk cornstarch into chicken stock and bring to a simmer. Add Chobani 2% plain Greek yogurt to sauce and heat gently but do not simmer. Season to taste with salt and pepper. Remove from heat and reserve warm.
Place turkey cutlets between two pieces of plastic wrap and pound thin. Marinate with ¾ cup Chobani 2% plain Greek yogurt. Combine breadcrumbs, parmesan cheese and a pinch of salt and pepper. Remove cutlets from yogurt and dredge in breadcrumb mixture to coat.
Heat a sauté pan over medium high heat and add olive oil. Sauté cutlets on both sides until golden brown and turkey is cooked through. Repeat with remaining cutlets and hold cooked cutlets in a 200° oven until ready to serve. Serve 2 cutlets per portion topped with creamy mushroom sauce.