Top with red onion, avocado, cilantro, salt and red pepper flakes. Squeeze the lime juice in, as well.
The fun part: Use your hands to squeeze, squash, and "smash" all of the ingredients together, for at least 1 minute. This manual action helps break down the kale fibers, and can't be achieved using utensils. The avocado will disappear into a creamy dressing coating the kale. You know it's ready when the kale shrinks in volume and gets darker in color.
If desired, top salad with seeds for an added crunch before serving.