To make the ragù alla bolognese, heat the olive oil in a large heavy-based stockpot over medium heat. Add the onion and cook for 2 minutes. Add the carrot and celery, then cook, stirring, until the onion is soft (approximately 3 minutes). Add the beef and pork mince (ground meat) to the stockpot with vegetables. Cook, stirring with a wooden spoon, breaking up any lumps until the mince is lightly browned all over. Add the red wine and cook for about 5 minutes or until the wine has reduced. Stir in the Italian passata, tomato paste, water and peas. Season with salt to taste and bring to the boil. Reduce the heat to low and simmer for approximately 1 hour or until the ragù has reduced to your required consistency. Stir the ragù alla bolognese occasionally so that the sauce does not stick to the pot and burn, then remove from the heat. Add more water to the ragù alla bolognese, as needed to keep the sauce lovely and moist.
Preheat the oven to 180°C conventional oven/ 160°C fan-forced (350° Fahrenheit/Gas 4). Grease a baking dish with butter or margarine.
To make the Besciamella sauce, melt the butter in a medium-sized saucepan over medium heat until foaming. Add the flour and stir with a wooden spoon to form a smooth paste (a roux). Allow the flour and butter mixture to cook for a minute (but do not allow it to brown). Remove from the heat. Slowly pour the cold milk into the roux, stirring constantly, until the mixture is smooth. Add the bay leaf and return to medium heat. Cook, stirring with the wooden spoon until the Besciamella comes to the boil and thickens (approximately 10 minutes). Remove from heat. Season with salt to taste and stir in freshly grated nutmeg. Set aside to cool slightly.
Meanwhile place a large pot with water on high heat and bring to the boil. Add a pinch of salt and rigatoni pasta to the boiling water and cook for ¾ of the ‘al dente’ cooking time – refer to the cooking time specified in pasta packet instructions. Drain the pasta, then add to the stockpot with ragù alla bolognese. Toss to combine.
Spread 1/4 of the Besciamella sauce over the base of the baking dish. Ladle 1/2 of the rigatoni pasta with ragù alla bolognese over the Besciamella layer, using the back of a ladle to press it down and level it. Spread 1/4 of the Besciamella sauce over the ragù alla bolognese. Add a layer of 1/2 of the sliced eggs, followed by a layer using 1/2 of the Provolone cheese cubes. Sprinkle 1/3 of the Parmigiano Reggiano cheese on top of the Provolone. Continue layering using the remaining rigatoni pasta with ragù alla bolognese (once again pressing it down with a ladle), 1/4 of the Besciamella sauce, remaining sliced eggs and Provolone cheese. Finish with a layer of Besciamella sauce and remaining Parmigiano Reggiano sprinkled to cover the Pasta al forno (pasta bake) and a few knobs of butter (or margarine) on top.
Bake in a preheated oven for 25 minutes. Change to the grill setting of the oven (same oven temperature). Brown under the grill for 5 minutes or until lightly golden on top. Remove from the oven and allow to rest for a minimum of 10 minutes before serving.
Cut the Pasta al forno into 6 portions and serve – buon appetito.