Thinly sliced cabbage is rarely served in the U.S., but it’s a standard accompaniment for tonkatsu (pork katsu), chicken katsu, or other deep fried main dish in Japan.
Crisp and crunchy raw cabbage goes very well with deep fried food. When you eat, sosu is poured over both fries and cabbage. Dressing is rarely used.
It is almost impossible to manually slice cabbage thinly, unless you are an accomplished cook. Many Japanese rather use a mandoline slicer, which saves time and efforts.
To make it right, don’t peel off cabbage leaves from the head. Instead, just slice a whole or a block of cabbage using a mandoline slicer. Otherwise, cabbage will be too soft to use a slicer.