Thaw. Cover, and put in 325° oven. Braise for 3-4 hours, turning every hour or so. Add more liquid (water, wine, or tomato sauce) if needed. (The liquid should come to about 1/3 of the way up the pork.) Meat is done when it’s practically falling apart.
Slow cooker: Thaw. Empty freezer bag into the slow cooker. Cook on high for 4-5 hours or on low for 7-8 hours.
Instant pot: Thaw. Cook on high pressure for 50 minutes and allow for a natural release for 10 minutes before switching to a quick release.
Shred and add back to pot and stir. Cook 1 to 2 pounds pasta according to package directions. Top pasta with ragu and Parmesan.