I would steam the cabbage until it's just going soft. Fry some pancetta to how you like it, add some shallots, then add the cabbage....cream/creme fraiche...season well...then add to cooked pasta.
Personally I don't like cabbage.
I would fry off the pancetta as the pasta was cooking. The cabbage would be firm and fresh and I would shred it finely. As the pancetta was nearing done I would add cabbage and stir through until it began to wilt. Add cream or whatever and heat through then add pasta.
There's no need to cook the cabbage separately once you've cooked off onion, garlic and pancetta, add the shredded cabbage along with a good glug of wine/sherry/vermouth/cider and bung on a lid and let the cabbage steam that way. After 3 minutes or so, take off the lid and cream and seasoning, lett bubble and then at the end add parmesan.