Heat oil in large skillet with a lid, over medium high heat.
Cut pork belly into even sized pieces, about 4 inches by 2 inches each. Dry the belly pieces with paper towel then season all pieces well with the Porchetta Rub.
In batches, brown all of the belly pieces on all sides, about 6 minutes per batch. Move to a plate when all the pork is browned.
Add the onions, carrots and celery to the pan. Season with salt and pepper and sauté until soft, about 5 minutes. Scrape up the brown bits on the bottom of the pan while stirring the vegetables.
Add the wine and reduce heat to medium. Simmer until wine has reduced to half.
Add the pork back in to the pan with the vegetables and add enough vegetable stock to just cover the pork. Bring to a simmer then cover with lid.
Cook for an 1.5 hours or until the pork is very tender.
Remove pork and shred in to bite size pieces.
Add shredded pork and the chopped cabbage back into the pan and simmer until liquid is reduced to about half.
Cook fettuccine according to the package instructions.
Drain cooked fettuccine and add to skillet with the pork and vegetable to combine.
Garnish with grated Parmesan and season with fresh ground pepper.
Notes
* Note: You can substitute another type of cabbage for the Savoy, but you will probably lose some of the texture that Savoy cabbage keeps during cooking.