Preheat oven to 200ºC.
Place turkey mince, prawn meat, egg whites, thickened cream, half the tarragon and parsley into a bowl, season with salt and pepper and mix to combine. Refrigerate for 30 minutes.
Spread stuffing on inside of turkey breast and roll to enclose, tie with butcher's string and wrap in muslin securing the ends with string.
Place in roasting pan skin side down and add ½ the wine and chicken stock. Roast for 30 minutes.
Remove muslin, turn breast to skin side up. Drizzle with oil, salt and tarragon sprigs. Add remaining wine and chicken stock and roast for another 30 minutes.
Remove turkey from pan and rest in a warm place.
Place pan juices in a saucepan with brandy, cook for 2 minutes and add cream then simmer for 4-5 minutes or until thickened.
Add remaining chopped herbs and serve with turkey breast and roast potatoes.