Rinse the quinoa in cold water. Boil 2 cups of salted water, add the quinoa, return to a boil and cook on low for 20 minutes. Set aside uncovered to cool while you prepare the rest of the ingredients.
Chiffonade , or chop the kale finely; place in a large serving bowl.
Add the carrots, scallions, celery, fresh herbs, walnuts, dried cranberries, and chicken if using.
Measure the lemon juice and olive oil into a 1 cup glass measuring cup. Add the garlic, zest, salt, and pepper. Whisk to blend and pour over the ingredients.
Add the roasted pumpkin cubes. Toss to distribute and coat evenly. Cover and Chill or Serve immediately at room temperature.