In a large saute pan, add the mushrooms, garlic and onions. Add half of the chicken broth, cover and cook over medium heat for 10 minutes.
In a separate bowl, combine the turkey, poultry seasoning, onion powder, egg white and bread crumbs. Divide the turkey into 4 equal parts. shape them into longer, thinner oval steaks.
Add the steaks to the pan. Stir the remaining broth and packet of brown gravy mix in the can until combined. Mix in the Worcestershire sauce, then add to the pan. Add in the fingerling potatoes, cover and cook for another 20 minutes, checking occasionally.