Mix tuna and the remaining ingredients except for the soup and milk. Spread the tuna mixture on the dough.
Roll up, beginning at the wide side. Seal by pinching the end of the dough into a roll. Place sealed edge under on baking sheet. Bake for 15 to 20 minutes, until lightly browned.
Meanwhile, heat the soup and 1/2 can milk in a saucepan. Slice the roll and serve with the mushroom gravy.