Rinse and drain the curly kale.
Heat some olive oil in a large pan and fry the pancetta until crispy. Add the balsamic vinegar and a drizzle of, reduce it to a syrupy consistency. Either turn off the heat and set aside, or carry on cooking.
5 minutes before serving, reheat it and add the drained kale, then stir -fry for a couple of minutes, season to taste, and gently sauté under cover until tender.
Cut the chestnuts in half and add to the kale.
Taste and adjust the seasoning, sweetness/sourness to your liking.