Prepare the cabbage: Remove outer leaves and core from the cabbage. Cut into quarters and slice thinly with a sharp knife or mandoline.

Sauté aromatics: Melt butter in a large pot over medium heat. Add chopped onions and cook until translucent, about 5 minutes.

Add cabbage: Stir in the shredded cabbage and cook for 5 minutes, stirring frequently, until it begins to wilt.

Add remaining ingredients: Stir in apples, vinegar, sugar, bay leaf, cloves, juniper berries, and apple juice. Season with salt and pepper.

Simmer: Reduce heat to low, cover, and simmer for 45-60 minutes, stirring occasionally, until cabbage is very tender.

Adjust seasoning: Remove bay leaf and whole spices. Taste and adjust seasoning with more vinegar, sugar, or salt as needed.

Serve: Transfer to a serving dish and serve warm as a traditional side to roasted meats.