Prep the greens by soaking in a baking soda and water bath, then dry completely.
Blend all vinaigrette ingredients in a small blender or food processor until smooth.
Chop the peanuts and roasted red peppers.
Using a food processor, pulse the kale and cabbage in batches until very finely chopped, stopping before the greens become too mushy. If excess moisture is released, gently pat dry with a paper towel. Transfer to a large bowl.
Toss the kale and cabbage with some of the dressing and massage with your hands for about a minute until tender. Add peanuts, peppers, green onions, and remaining dressing, then toss to combine.