Over medium heat, bring a pot of vegetable oil to 350 degrees.
Add 2 tablespoons of the cooked risotto to the beaten egg. Remove and allow excess to fall off. In the palm of your hand, flatten the rice and fill with 1-2 pieces of guanciale, a few cubes of scamorza, tomato paste, chopped parsley and a sprinkling of pecorino. Enclose the center filling with rice.
Roll the ball around in the breadcrumbs and set into the fryer. Fry until golden brown.
Once the arancini are cooked, drop a few sprigs of parsley into the oil. Allow to fry for a few seconds and remove. Garnish arancini with parsley.