Bring the broth and 1/4 teaspoon salt to a boil in a medium saucepan over medium-high heat. Stir in the rice, reduce the heat to low and simmer until tender, about 20 minutes. Spread on a parchment-lined baking sheet and let cool completely.
Combine the pine nuts, mozzarella, fontina and parsley in a bowl; set aside.
Beat the eggs in a large bowl, then stir in the cooled rice, the parmesan and 2/3 cup breadcrumbs. Shape the mixture into sixteen 1 1/2-inch balls.
Put the remaining breadcrumbs in a shallow bowl. Press your finger into the center of each rice ball, insert 2 teaspoons of the mozzarella mixture, then pinch the rice around the filling to enclose. Roll the balls in the breadcrumbs and place on a parchment-lined baking sheet. Loosely cover and refrigerate, at least 1 hour or overnight. (If refrigerating overnight, roll in more breadcrumbs before frying.)
Heat 1/2 inch vegetable oil in a large saucepan over medium heat until a deep-fry thermometer registers 350 degrees F. Working in batches, fry the rice balls, turning, until golden brown on all sides, about 4 minutes. Remove with a slotted spoon and drain on paper towels; season with salt.