Shred the cabbage and grate the carrots.

In a large skillet, melt the butter over medium heat and add the diced onions. Sauté until the onions become translucent, about 3-5 minutes.

Add the shredded cabbage and grated carrots to the skillet. Stir and cook for another 5 minutes until the cabbage starts to soften.

Pour in the apple cider vinegar and sprinkle the sugar over the cabbage mixture.

Add salt and black pepper to taste.

Continue to cook, stirring occasionally, for another 5-7 minutes until the cabbage is tender but still has a slight crunch.

Taste and adjust seasoning if needed.

Transfer the cooked coleslaw to a serving dish and serve warm.