How to Make It
Preheat oven to 325°F.
Heat olive oil in a Dutch oven over medium-high. Sprinkle pork with 1/2 teaspoon salt. Add pork to pan; cook until well browned all over, about 8 minutes. Remove pork from pan.
Add onion, fennel, and garlic to pan; cook, stirring occasionally, 5 minutes. Add tomatoes and their juices; break tomatoes up with the back of a spoon or your hands. Stir in anchovies, oregano sprigs, bay leaves, red pepper, and remaining 1/2 teaspoon salt. Nestle pork into tomato mixture. Cover and bake at 325°F until pork is very tender, about 1 hour and 30 minutes. Carefully remove pork from Dutch oven. Shred pork using 2 forks; stir shredded pork into tomato mixture. Discard bay leaves and oregano sprigs.
Cook pasta according to directions, omitting salt. Drain; reserve 1 cup cooking liquid. Add pasta to Dutch oven; toss gently to coat, adding reserved cooking liquid as necessary to reach desired consistency. Sprinkle with cheese and oregano leaves.
Slow Cooker Method - Brown pork as directed in step 2, substituting a skillet for the Dutch oven. Add pork, onion, fennel, garlic, tomatoes, anchovies, oregano sprigs, bay leaves, red pepper, and remaining 1/2 teaspoon salt to a 6-quart slow cooker. Cover and cook on LOW until pork is tender, 5 to 6 hours. Shred pork; discard bay leaves and oregano sprigs. Follow recipe as directed in step 4.