1. Start by making the risotto. Bring the stock and mushrooms to a boil then reduce to simmer.
2. Heat butter in a second large saucepan over medium heat.
3. Sauté shallots and garlic for five minutes.
4. While stirring, add the rice and cook until well toasted, about five minutes.
5. Add the wine. Cook until completely absorbed by the rice.
6. Remove the mushrooms and reserve.
7. Add a ladleful of stock to the rice, stirring often until completely absorbed.
8. Add another ladleful of stock and repeat until the rice is al dente, about 20 minutes.
9. Chop the reserved mushrooms and stir into the risotto.
10. Stir in the Parmesan.
11. Season to taste with salt and pepper. Allow to cool.
12. Put flour, eggs and breadcrumbs in three separate bowls.
13. Using a few tablespoons of risotto, roll into a ball, stuffing a cube of mozzarella inside.
14. Repeat with remaining risotto to make 12 balls.
15. Heat a few inches of oil in a heavy pot to 340°F.
16. Dip the risotto balls in flour, then egg, then breadcrumbs.
17. Working in batches, fry until golden brown, about 2 to 3 minutes. Drain on paper towel.
18. Best served with truffle or garlic aioli.