Heat the olive oil in a large heavy pot over medium heat. Cook the pork, turning often, until evenly browned for about 10 to 12 minutes.
Transfer to a platter and drain off pan drippings. Wipe out any burned bits from the pot but leave the golden brown pieces to flavor the sauce.
Add the onion and garlic to the pan and cook stirring continuously until the onion is translucent, about 4 minutes.
Add the wine and cook for about 2 minutes.
Add the tomatoes, rosemary and thyme and season with salt and pepper to taste. Cook for 5 minutes.
Add the meat to the pan and mix it with the rest of the ingredients.
Bring the sauce to a boil, then reduce heat to very low and simmer for 2 1/2 to 3 hours.
FOR THE POLENTA
Bring the water to a boil over medium-high heat. Add 1 tablespoon of salt.
While whisking gently, slowly pour the polenta into the boiling water.
Turn down the heat to low and whisk continuously until the polenta has thickened enough that it doesn't settle back on the bottom of the pan when you stop stirring.
Stir vigorously every 1 minute or so, making sure to scrape the sides, bottom, and corners of the pan. Cook 30 minutes for softer polenta or 40 minutes for thicker polenta.
Stir in the Pecorino Romano and butter.
Place the polenta covering the bottom of the plate and pour the Pork Ragú on top. Garnish with finely chopped parsley.