Take your vegan cheese slices, put them on top of each other, and cut the into thinner slices about 5 cm / 2 inches long. You need to get a small cheese stick that we'll put inside the supplì.
On a table, prepare 1 plate full of breadcrumbs, 1 bowl with the soy milk, 1 large empty plate, the olive oil, and the cheese sticks.
Take the leftover risotto rice out of the regrigerator. TIP: if you make the risotto from scratch for the supplì, you need to make it very thick, and you need to let it cool down competely before you can use it for the supplì.
Grease up the palm of your hands with a little olive oil, then place a spoonful of the leftover risotto rice in your left hand.
Flatten the rice between the palms of your hands. Then apply gentle pressure with your index finger in the centre of the flattened rice, to create a little nest for the cheese.
Place the cheese stick in the rice. Then with both hands, wrap the rice around the cheese, rolling it between the palms of your hands. Make sure the cheese stick is fully sealed by the rice.
At the end you should get a smooth and compact rice croquette that resamble a small cilinder shape with round ends. See picture. Set aside on a clean plate and repeat the step until you run out of rice.
For the breading, take each supplì, one by one, gently dip it in the bowl with the soy milk, then roll it in the breadcrumbs. Now take it in your hands, and add more breadcrumbs, pressing between the palms of your hands. Make sure the supplì is completely coated with breadcrumbs, then set it aside on a clean plate.
In a pot, add the frying oil and bring it to 170°C (340°F). Throughout the frying process, try to keep the oil between 160°C (320°F) and 180°C (356°F). Prepare a large platter lined with kitchen paper.
Gently lower the supply in the oil. Be careful. Add up to a max of 4 supplìs at a time. Gently move the supplìs around to cook evenly. Fry in the oil for about 5 minutes, until they turn of a nice brown colour. TIP: if the oil is too hot they'll cook too fast on the outside and become too dark. Keep the oil around 170°C (340°F) for best result, by checking with a kitchen thermometer.
Take the supplìs out of the oil, let drip excess oil away, and rest on a large platter lined with kitchen paper.
Let cool down for at least 3 minutes (careful they are very hot inside and you can get burned), then enjoy, eating them with your hands!