Prepare the Cabbage and Carrots: In a large bowl, combine the shredded green cabbage, purple cabbage, and carrots. Sprinkle 1 teaspoon of salt evenly over the vegetables. Toss well to coat. Let the mixture sit at room temperature for at least 30 minutes, or up to an hour. This crucial step is key to drawing out excess moisture that would otherwise make your coleslaw watery.

Drain Excess Water for Crispness: After resting, the cabbage will have released a significant amount of water. Transfer the cabbage mixture to a colander and, working in batches if necessary, firmly squeeze out as much liquid as you can. You can use your hands or press it against the side of the colander with a spoon. This step is absolutely essential for achieving and maintaining that perfectly crisp texture.

Make the Dressing: While the vegetables are resting, prepare the dressing. In a medium bowl, whisk together the mayonnaise, apple cider vinegar, and granulated sugar until smooth and well combined.

Combine and Dress: Transfer the squeezed, drained cabbage and carrots back to the large bowl. Pour the creamy dressing over the vegetables. Toss gently but thoroughly until all the vegetables are evenly coated.

Season and Chill: Stir in 1/2 teaspoon of black pepper. Taste and adjust seasoning if needed, adding a pinch more salt or pepper. For the best flavor and texture, cover the bowl and refrigerate the coleslaw for at least 1 hour before serving. This allows the flavors to meld and the vegetables to absorb the dressing without becoming soggy. Garnish with additional black pepper just before serving, for that classic look.