In an extra-large bowl combine the kale, salt, and olive oil. Using your hands, rub the kale to help soften it and brighten its color (personally, I.
prefer to steam it for a few mins). Rinse the kale in a colander under cool running water; drain well and return to the bowl. Add the savoy cabbage, purple cabbage, and carrots; toss to combine. Set slaw aside.
For the dressing, in a food processor or blender combine the parsley, mayonnaise, sour cream, green onion, vinegar, tarragon, sugar, and garlic. Cover and process or blend to combine.
Add the dressing to the vegetable mixture; toss to coat. Sprinkle pepitas over the salad.