In a large bowl mix ground beef, rice mixture from Rice-A-Roni, half a packet of the seasoning mix from the Rice-A-Roni and the egg. Shape into medium size meatballs.
Heat a large nonstick skillet on medium high and add oil. Add meatballs and brown on all sides. Turn heat down to medium low, cover with lid, and continue to cook until cooked through, about 7-9 minutes.
In a large measuring cup or bowl, measure water and add gravy mix. Mix with fork or whisk and add to meatballs in the pan. Turn heat to low, cover and cook 35-40 minutes or until rice is cooked, stirring occasionally and adding additional 1/2 cup water gradually as needed if gravy becomes too thick.
During the last couple of minutes of cooking, add black pepper. Serve with mashed potatoes, topping with gravy.