Sauerkraut is lacto-fermented white cabbage.
Unlike pickles it doesn't contain vinegar, but can be used in exactly the same way.
Use it as a side dish, with hot or cold meats, mash it with potatoes (like the Dutch!), have it with smoked mackerel, the list is endless.
Nutritional values per 100g:
Energy 102Kj/ 24kCal
Fat 0.2g
of which saturates <0.1g
Carbohydrates 3.3g
of which sugars 1.2g
Protein 2g
Salt 1.2g
Fibre s 2.2g