Chunky Pork and Mushroom Spaghetti

1 1/2 lb. boneless country-style pork ribs
1 C. frozen onions, celery, bell pepper, and parsley blend (from 12 oz. bag), thawed
29 oz. can tomato puree
14.5 oz. can diced tomatoes with basil, garlic, and oregano, undrained
1 Tbsp. Worcestershire sauce
1 tsp. sugar
1 tsp. fennel seed
8 oz. sliced mushrooms
16 oz. spaghetti
1 Tbsp. olive oil
grated Parmesan cheese

In 3-4 qt slow cooker, mix all ingredients except mushrooms, spaghetti, and cheese.
Cover and cook on low 8-10 hrs.
Using 2 forks, break pork into bite size pieces in cooker. Stir in mushrooms. Increase to high, cover, and cook 15-20 min. Meanwhile, cook and drain spaghetti according to package directions.
Stir oil into sauce. Serve over hot spaghetti and sprinkle with cheese.