Step 1: For the risotto, heat 2 tbsp olive oil in a large pot over medium heat. Add chopped onion and sauté until softened and translucent, about 5-7 minutes. Add minced garlic and cook for another minute until fragrant.
Step 2: Add Arborio rice to the pot and toast, stirring constantly, for 2-3 minutes until the edges of the grains are translucent.
Step 3: Pour in white wine and stir until completely absorbed by the rice.
Step 4: Begin adding hot chicken or vegetable broth, one ladleful at a time, stirring frequently. Wait for each ladleful to be almost fully absorbed before adding the next. Continue this process until the rice is al dente, about 20-25 minutes. Stir in the saffron-infused broth if using. The risotto should be creamy but not soupy, and still quite firm.
Step 5: Remove from heat. Stir in butter and grated Parmesan cheese until melted and fully incorporated. Season with salt and black pepper to taste.
Step 6: Spread the risotto in a single layer on a baking sheet or large platter. Cover loosely with plastic wrap and refrigerate for at least 2-3 hours, or preferably overnight, until completely chilled and firm.
Step 7: For the ragù filling, heat 1 tbsp olive oil in a medium saucepan over medium heat. Add ground beef (or mixed) and cook, breaking it up with a spoon, until browned. Drain any excess fat.
Step 8: Add diced carrots, celery, and onion to the pan. Sauté until softened, about 5-7 minutes.
Step 9: Stir in tomato paste and cook for 1 minute. Pour in crushed tomatoes and a splash of broth or red wine if desired. Season with dried oregano, bay leaf, salt, and pepper.
Step 10: Bring to a simmer, then reduce heat to low, cover, and cook for at least 30 minutes, or longer for deeper flavor, stirring occasionally. The ragù should be thick and not watery. Remove the bay leaf. Let cool completely.
Step 11: Set up your workstation: chilled risotto, cooled ragù, cubed mozzarella, and your breading station (flour, beaten eggs, breadcrumbs).
Step 12: Take about 1/4 cup of the chilled risotto in your palm. Flatten it into a disc. Place a spoonful of ragù and a cube or two of mozzarella in the center.
Step 13: Carefully cup your hands around the filling and mold the risotto into a tight ball, ensuring no filling peeks through. If the rice feels too sticky, lightly dampen your hands. Repeat with the remaining risotto and filling.
Step 14: Set up your breading station: one shallow dish with all-purpose flour, one with beaten eggs (with a splash of milk or water), and one with fine breadcrumbs. Roll each arancino first in flour, shaking off any excess.
Step 15: Then dip it in the egg mixture, allowing excess to drip off. Finally, roll it thoroughly in breadcrumbs, pressing gently to ensure a complete and even coating.
Step 16: Heat about 3-4 inches of frying oil in a large, heavy-bottomed pot or deep fryer to 350-375°F (175-190°C). Use a kitchen thermometer to monitor the temperature.
Step 17: Carefully lower 3-4 arancini into the hot oil, ensuring not to overcrowd the pot. Fry for 4-6 minutes, turning occasionally, until deeply golden brown and crispy all over.
Step 18: Remove the fried arancini with a slotted spoon and place them on a wire rack lined with paper towels to drain excess oil. Serve immediately with marinara sauce for dipping.