In a big bowl, put half of the buffalo mozzarella diced, ricotta, 2 tablespoons of grated Parmigiano Reggiano, the 2 egg yolks, the meat, and the shavings. Add a pinch of salt and pepper and nutmeg to taste.
Using your hands, knead the filling until it reaches the right texture, adding an extra egg yolk if necessary. Fill the cannelloni by hand or with a pastry syringe.
In an oven tray, put the cannelloni on a bed of tomato ragout. With a spoon add some more sauce on the cannelloni. Each portion is made of three cannelloni. Cut the rest of the mozzarella in stripes and on each portion put one stripe of mozzarella and a basil leaf.
Cook in the oven at 180º for 15 minutes. When ready, sprinkle with grated Parmigiano Reggiano and serve.