These little bites of risotto are crunchy on the outside, creamy inside, with a woodsy flavor.
In a small bowl, soak porcini in warm water until soft, about 20 minutes. Remove, squeeze gently, and chop coarsely. Set water and mushrooms aside.
In a medium saucepan over low heat, saute garlic and shallot in 1 tablespoon olive oil until translucent, 2 to 3 minutes. Turn heat up to medium and add white mushrooms. Cook until soft, about 5 minutes. Add half the porcini.
In another saucepan, bring stock to a low simmer and keep it there.
Add rice and remaining olive oil to mushroom mixture and stir until all grains are well coated. Pour in wine, stirring constantly. Cook until rice absorbs most of the wine. Repeat with mushroom liquid.
Add 1 cup stock, stirring frequently to avoid sticking. Cook until most of the stock is absorbed. Repeat with as much of remaining stock as needed, adding cup by cup. Start testing for doneness after third or fourth cup; rice should be al dente, with a creamy consistency but a little drier than a regular risotto so the balls hold together. The process should take 20 to 30 minutes. Stir in remaining porcini.
Season with salt and pepper, and stir in butter and Parmesan. Spread in a baking pan to cool. Cover and refrigerate until cold, about 1 hour.
Cut Fontina into tiny cubes, smaller than 1/4 inch. With moist hands (keep a bowl of warm water close by), press a cube of cheese into center of about 1 tablespoon of rice. Enclose cheese in rice and roll with both hands until ball becomes compact and round. The risotto balls can be made 1 or 2 days ahead up to this point; refrigerate, covered.
On the day of the party, dredge risotto balls in flour. Deep-fry in vegetable oil at 375 degrees until crisp and brown on the outside. Serve immediately, or keep at room temperature and reheat in a 375-degree oven until hot. Roll in chopped fresh parsley if desired.