Trim fat from pork; cut pork into 1/4-inch cubes.
Remove casing from sausage. Cook sausage in a Dutch oven over medium-high heat until browned; stir to crumble. Remove sausage from pan with a slotted spoon. Add onion to pan; saute 4 minutes or until lightly browned. Add pork, and sauté 5 minutes. Add sausage, rosemary, salt, and pepper. Stir in broth and wine, scraping pan to loosen browned bits. Bring to a boil; cook for 5 minutes. Add tomatoes, and bring to a boil. Reduce heat, and simmer 30 minutes. Serve over pasta, and sprinkle with cheese. Garnish with rosemary sprigs, if desired.
Freezing instructions: After cooking ragout, place in a large heavy-duty zip-top plastic bag. Cool completely in refrigerator; freeze for up to 1 month. To reheat, place bag in a large pot of boiling water (do not unseal bag). Cook 15 minutes or until thoroughly heated. Remove the bag from water using tongs. While ragout is reheating, grate the cheese, and cook the pasta according to package instructions, omitting salt and fat.