In a small bowl, whisk together the shallot and Newman's Own dressing. Set aside for at least 10 minutes to soften the shallot.
Meanwhile, use a sharp knife to very finely shred the kale. You want it to be sliced into very fine, almost thread-like strips.
Remove the outer leaves from the brussels sprouts. Then, finely shred using a mandolin (be very, very careful) or shredding tool of choice (e.g., food processor fitted with shredding attachment). Note: you won't be able to safely shred the brussels sprouts completely using the mandolin, so finely chop what you can't shred with a knife.
Add the hemp seeds, sunflower seeds, and sesame seeds to a large sauté pan. Turn the heat on low and gently toast for 2 minutes, or until the seeds just begin to turn golden and waft a light toasted scent. Let cool slightly.
In a large serving bowl, combine the kale, brussels sprouts, and radicchio.
Pour the shallot and dressing mixture over the salad, and toss to coat.
Add the toasted seeds and nutritional yeast, and toss again.
Season to taste with sea salt and black pepper.
Allow the salad rest for 5 minutes to gently wilt the greens.
Taste. If desired, add more dressing and/or a light drizzle of maple syrup (to gently sweeten), and toss to coat
Divvy the salad up into bowls, top with the avocado (if using), and serve immediately.
Refrigerate leftover salad (without avocado) in an airtight container for up to 3 days.