The Kapusta I grew up on, delicious on its own or with kielbasa, and is the same filling we use for Pierogies It is labor intensive to make but oooh so worth it.
1 big pot, gently boil 2 medium heads of shredded cabbage in lightly salted water till tender to the taste. Drain and cool. I use an ice water bath to cool quick. Squeeze the cabbage using cheese cloth to remove as much water as possible. Set aside.
2. In large pan melt 1 to 1 and 1/2 sticks of butter, add 2 large diced sweet onions and cook till carmelized light brown. Towards end of process add in about 6 finely diced garlic cloves.
3. In 3rd big pot cook down 32 ounce bag of good sauerkraut to steam off most of the liquid. Stir frequently and use med heat, you just want to cook off the liquid and condense the flavors.
4. Add in your drained and squeezed sweet cabbage, butter and onions, and mix well to blend. Add salt and pepper to taste, I like lots of black pepper, and additional butter to taste as well.
5. Eat as is, with rye bread, add in sliced or diced kielbasa, or use for pierogie filling.
I have yet to meet someone to try this Kapusta and not love it. Enjoy.