Step 1

Bring 4 cups chicken broth and saffron threads to a boil in a saucepan over high heat. Stir in Arborio rice, return to a boil, then reduce heat to medium-low, cover, and simmer until the rice is tender, yet still a little firm, about 16 minutes.

Step 2

Heat olive oil in a large saucepan over medium heat. Stir in onion, and cook for one minute, then stir in garlic, and continue cooking until the onion has softened and turned translucent, about 3 minutes. Stir in wine, spinach, and butter, and bring to a boil. Reduce heat to medium-low, and fold in cooked rice and Parmesan cheese; cook a few minutes until the mixture is a little stiff. Spread onto a baking sheet, and cool in the refrigerator until completely cold, 4 hours to overnight.

Step 3

Once the rice mixture has cooled, form the arancini by enclosing a cube of mozzarella cheese in about 3 tablespoons of the rice to form a 1 inch ball; set aside. When you have finished making the balls, place flour, eggs, and bread crumbs into separate, shallow bowls. One-by-one, gently roll the arancini in the flour to coat, then shake off excess. Dip into beaten egg, then roll in bread crumbs; set aside.

Step 4

Heat the oil in a deep-fryer or electric skillet to 350 degrees F (175 degrees C).

Step 5

Deep fry the arancini 5 or 6 at a time in the hot oil until golden brown, about 4 minutes. Be sure to roll the arancini around with a metal spoon as they cook so they are evenly browned on all sides. Drain on paper towels, and serve hot.