Place 2 cups shredded cabbage in a large colander set over a sink or large bowl. Sprinkle with ½ tsp Kosher salt, then toss to thoroughly coat. Allow cabbage to drain for 10-15 minutes.

In a large mixing bowl, whisk together mayo, sour cream, garlic salt, and the juice of 2 limes.

Transfer the drained cabbage to the large mixing bowl with the dressing, then add thinly sliced red onion, scallions, and ¼ cup fresh cilantro. Toss well, then refrigerate until needed, at least 30 minutes. Taste, adjust seasoning, then serve!