Wash the cabbage and parsley. Discard the onion's skin.
Finely chop the onion, parsley, and cabbage, keeping the ingredients separate.
In a glass, dissolve the tomato paste in 100 ml of warm water.
In a high-sided saucepan, melt the butter with the olive oil.
Add the onion and a pinch of salt, stir, and fry gently for 2 minutes. Then, add the cabbage, stir, and cook for 3 minutes over low heat on a small burner, then add the diluted tomato paste.
Stir, add the red wine, and cook for five minutes over medium-low heat on a small burner.
Add the sugar, soy sauce, water, and half of the finely chopped parsley, setting aside the rest for garnish, then stir.
Cook over medium-low heat for about 30-40 minutes. Towards the end of cooking, add water if necessary; conversely, if the sauce is too runny, continue cooking.
Then turn off the heat, taste, and add salt if needed. Add the remaining parsley and stir.