Preheat the oven to 325°F.

Heat the olive oil in a large enameled or stainless steel Dutch oven over medium-high heat. (Do not use cast iron.) Cut the pork into three equal pieces and season well with salt and pepper. Brown the meat on all sides, then remove from the Dutch oven and set aside on a plate. Using the fat remaining in the pot, cook the shallots, carrots, and celery for 10 minutes until the vegetables are softened. (If there is a lot of fat, drain some off before sautéing the vegetables.)

Add the tomato paste, stir it into the vegetables and cook for 3 minutes. Add the Herbes de Provence, cook for 30 seconds, then deglaze the pan with the wine. Cook for 5 minutes, then add the San Marzano tomatoes and break them up with the back of a spoon. Add the passata and bay leaves, then season well with salt and pepper.

Add the pork pieces back to the Dutch oven, then add the chicken stock. Bring to a boil, then cover and place in preheated oven for 3 1/2 hours.

When the pork is done, remove the meat and let cool while thickening the sauce; bring the sauce to a boil on the cooktop, then reduce heat and simmer about 20 minutes until thickened slightly. Shred the pork, and return to the sauce. Optional: can be made in advance and refrigerated. To serve, reheat on stovetop till just bubbling.

Cook the pasta in salted water until al dente. Add the cooked pasta to the ragoût, toss to coat, then divide among heated pasta bowls and serve, spooning additional sauce overtop.