Preheat the oven to 350 degrees. Wash and prick the potatoes with a fork. Bake the potatoes in the oven, for one hour. Cool the potatoes in the refrigerator overnight.
To make the ragu, begin by heating the olive oil in a large sauté pan or roasting pan over medium-high heat. Add the garlic and sauté until slightly browned, two to three minutes. Add the onion, carrots, celery, and bay leaves to the pan. Sauté until the vegetables start to caramelize, about five minutes. Season the boar with salt and pepper. Add the boar to the pan and brown on all sides. Once the boar is browned, add the tomato puree and wine and, with a wooden spoon, scrape the bottom of the pan to loosen any browned bits. Add the rosemary sprigs and bring to a boil, adding a bit of water if needed. Reduce the heat to low and cook gently, uncovered, until the meat is very tender and most of the liquid has cooked down, about three to four hours.
While the sauce simmers, make the gnocchi. First, peel the potatoes then pass them through a potato ricer into a large bowl. Add the egg yolks, Parmigiano-Reggiano and a generous pinch of salt and pepper. Lightly mix the egg mixture with the potatoes and fold in the flour until combined with the potato to create a smooth dough. Cover the dough with plastic wrap and let rest for one hour.
Once rested, pull off pieces of the dough and roll into ropes about ½-inch thick. Cut the ropes into 1-inch-long dumplings. Roll each dumpling gently in the palm of your hand, first into a ball, and then, with your thumb, taper the ends to resemble a football. Arrange the finished gnocchion a lightly floured cloth so that they are not touching, and let dry for 15 minutes. While the gnocchi are drying, bring a large pot of salted water to a boil. Add the gnocchi and remove them with a slotted spoon once they rise to the surface (about 45 seconds). Shock the gnocchi in ice water and remove once cool. In a large bowl, toss the gnocchi with olive oil and reserve.
When the meat is tender and the sauce has cooked down, use tongs to lightly break apart the braised boar. Add the reserved gnocchi and four tablespoons of butter to the pan with the boar sauce. Cook over low heat for one to two minutes to allow the gnocchi to marry with the sauce. Divide the pasta among warmed individual plates and top generously with freshly grated Parmigiano-Reggiano cheese.
Serve immediately and enjoy!