These golden stuffed rice balls—which resemble little oranges, or arancini—are a popular street snack in Sicily. Tony Mantuano's recipe calls for a stuffing of lamb, spinach, and two kinds of cheese, for a tangy bite and melty stretch.
In a medium saucepan, cook rice over medium heat in 4 cups of lightly salted water until all the water is absorbed, about 10–15 minutes. Remove from heat and spread the rice out on a sheet pan to cool. Season to taste with salt and pepper.
Heat olive oil in a sauté pan over medium-high heat. Add lamb and cook for 2 minutes, breaking it up with your wooden spoon and seasoning with salt and pepper; then add garlic. When lamb is completely browned, add spinach and cook until wilted. Set aside to cool.
When rice is cool, combine with 2 beaten eggs, ½ cup grated Pecorino Romano, and 4 grinds of black pepper. Set aside. In another bowl, mix remaining Pecorino Romano and panko. Set aside.
Shape rice mixture into 6 balls the size of small oranges and hollow out the centers. (Keep a bowl of water nearby to wet your hands; the rice can be sticky.) Fill each with a cube or two of sheep’s-milk cheese and 1–2 tablespoons lamb-spinach mixture. Seal rice ball by patching with more rice. Set aside on a baking sheet.
Fill a heavy-bottomed pot halfway with canola oil and heat to 350 F. While oil is heating, place flour, 3 beaten eggs, and panko-cheese mixture in three separate bowls. Roll the rice balls first in flour, then in the eggs, and finally in the panko-cheese mixture. Carefully deep-fry in the hot oil, turning frequently to cook evenly, until golden brown, about 7 minutes.
Remove arancini from the hot oil and let drain on paper towels. When cool enough to handle, about 3 minutes, transfer to a plate and serve immediately.
Can be made ahead and refrigerated 1–2 days before cooking.