Place the kale in the serving dish (to tenderize your kale, give the leaves a 30 second massage with your hands). In a small bowl, whisk together the dressing ingredients until well combined. Drizzle 2/3 of the dressing over the kale and toss until coated. Top with grapefruit, avocado, and walnuts. Drizzle remaining dressing over the top and serve.