Instructions:
- Prepare the Saffron Broth: Steep saffron threads in the warm broth. Keep warm on the stovetop.
- Start the Risotto Base: In a large heavy-bottomed saucepan, melt the 3 Tbsp butter. Sauté the minced onion until translucent. Add the Arborio rice and toast for 2 minutes, stirring constantly. Deglaze with the white wine, scraping up any browned bits from the bottom.
- Cook the Risotto: Ladle by ladle, gradually add the warm saffron broth to the rice, stirring continuously. Continue adding broth until the rice is al dente (about 20 minutes). It should be slightly firmer than standard risotto.
- Enrich the Rice: Remove the rice from the heat. Immediately stir in the grated Parmigiano-Reggiano, the 2 egg yolks, salt, and pepper. Spread the saffron rice onto a clean baking sheet to allow it to cool rapidly and set its structure.
- Make the Ragù Filling: While the rice cools, brown the ground meat in a large skillet. Drain excess fat. Add minced garlic and sauté for 1 minute. Stir in the tomato paste, crushed tomatoes, oregano, basil, and bay leaf. Simmer gently for 15 minutes until thickened. Remove the bay leaf and stir in the thawed peas.
- Assemble the Casserole: Grease a 9x13 inch oven-safe casserole dish. Spread half of the saffron rice evenly across the bottom. Layer the mozzarella cheese evenly over this rice base. Top with the entire meat ragù mixture. Finish by carefully spreading the remaining half of the saffron rice over the ragù, patting gently to seal the layers.
- Prepare the Crispy Top: In a small bowl, combine the Panko breadcrumbs, 3 Tbsp melted butter, and Pecorino Romano cheese. Sprinkle this mixture evenly over the top layer of rice.
- Bake: Bake in a preheated oven at 375°F (190°C) for 30 to 35 minutes, or until the edges are bubbling hot and the Panko topping is deep golden brown and crisp.
- Rest and Serve: Allow the casserole to rest for 10 minutes before slicing and serving. Garnish generously with fresh chopped parsley.