Slow and gentle cooking is required here with the lid on, which allows the cabbage to soften and stay moist.
For 4 persons:
Peel off and discard outer leaves of the cabbage and thinly slice it.
In a pan that will fit the cabbage ( which will reduce in size while cooking) heat the olive oil, add the pancetta and the onion. After couple of minutes add chopped garlic and the rosemary. Simmer until the onion becomes light brown in colour.
Now add the cabbage to the pan, give it a stir and start simmering on a low heat with the lid on for a minimum of 1 hour. Stir occasionally and add a bit of water if necessary.
Towards the end of cooking adjust the seasoning and add the vinegar.