Arancini (Rice Balls)

Chop the carrot, celery, and a third of the onion (1 1/2 oz.) and sauté in a saucepan with 3 Tbsp. olive oil over medium-high heat until softened and the onions are translucent. 

Add the beef, stirring often, until browned.

Add the tomato passata and a little salt and simmer over low heat for 1 hour (if necessary, adding a little water) to obtain a fairly thick meat sauce (if using a pressure cooker, it will take 20 minutes after pressurization). At the end of cooking, add the boiled peas along with some pepper and salt. Transfer it to a bowl and let it cool.

Chop the rest of the onion (around 3 oz.) and sauté it in a saucepan with 3 Tbsp. olive oil. Add the peeled tomatoes, a ladle of water, and a pinch of salt, and let simmer for 30 minutes. Purée it well. Add the rice and 1 qt. vegetable broth. Lower the heat and let simmer until dense (around 10 minutes). The rice should remain al dente. 

Turn off the heat and spread it out on a tray to cool. In the palm of your wet hand, shape 8-10 rice balls around the size of an orange, gently packing it until firm. Make a cavity, fill it with 1 tsp. meat sauce, 3 pieces mozzarella, then a little more meat sauce. Close the rice around the filling to form a cone shape, gently packing them firm again.

Heat the peanut oil to 350°F. 

Whisk together the flour and about 3/4 cup water to form a smooth batter. Place breadcrumbs in a shallow bowl. Dip the rice balls in the batter, then in plenty of breadcrumbs, pressing gently to adhere.

Fry 2-3 rice balls at a time for around 3-4 minutes, turning them gently to avoid breaking. Transfer to paper towels to drain. Serve immediately.