My husband still has difficulties with swallowing rough things such as raw cabbage. The following is a redaction from a recipe for Roode Kool Salade in The United States Regional Cookbook, edited by Ruth Berolzheimer, published in 1939.

1/2 cabbage , shredded
1 sweet onion, finely chopped
1 can slide beets, cut into strips
3 Tablespoons butter
Vinegar to tolerance/taste - I used red wine and tarragon, mixed
Salt to taste / tolerance
2 Tablespoons sugar (optional, may use other sweetener)

Set a pan of salted water to boil.
Add the cabbage and onion.
Cook until you thing you or your loved one can swallow it easily.
Strain cabbage and onion, put in a pretty bowl, and add butter immediately so it will melt.
Add in beets, salt, sugar, and a little vinager and mix together.
Add vinegar to taste: note that the salad will get milder if you let it stand for a bit. More vinegar can be sprinkler on if needed.
Optional:
Add quarters of hard-boiled eggs the top of the salad - will make it look prettier AND add protein.