Place the vegetable stock into a large saucepan and heat to a simmer on the back of the stove. Remove the rind from the butternut squash and grate on the large hole side of a box grater. Heat a wide-bottom pan over medium high heat. Sauté the onion in butter until soft. Stir in the rice and stir to coat. Add a couple ladles of the broth and stir until the broth is absorbed by the rice. Add couple more ladles and continue stirring until the broth is absorbed. Stir in the grated butternut squash. Continue stirring and adding more broth until the rice is cooked but still firm, about 20 minutes. Add the wine and cook during the last couple minutes. Stir in the parmesan cheese and season to taste with salt. Remove from the heat and spread out on a parchment lined baking sheet and allow to cool to room temperature.
Scoop the risotto into balls with a small ice cream scoop. Flatten a ball of risotto in the palm of your hand. Place a cube of the mozzarella cheese in the center.
Enclose the cheese with the risotto and roll into a ball between the palms of your hand.
To bread the balls of risotto, place the flour in small bowl, beat the eggs and milk together in another bowl and place the panko in another bowl. Roll the risotto balls in the flour to coat, dip in the egg and roll in the breadcrumbs. Fill a deep pot with the vegetable oil to a depth of 3 inches. Heat to 350°F. Fry in small batches until golden brown. Remove to plate lined with paper towels. Repeat with the remaining balls of risotto. Server while still hot.
Enjoy with a glass of Cakebread Cellars Annahala Ranch Pinot Noir