Steam or boil asparagus until crisp-tender. Drain asparagus, shock in cold water to stop cooking, blot dry on paper towels and cut into 1-inch pieces. Set aside.
Melt butter in large saucepan over medium heat. Add onion and sauté until transparent, 4 to 5 minutes, stirring occasionally.
Stir in Kitchen Accomplice Veggie Broth Concentrate or Vegan Plant-Based No-Bone Broth Concentrate, water and barley, and bring mixture to a boil. Beat eggs and lemon juice together in a bowl until smooth. Slowly whisk about a cup and a half of hot stock into egg-lemon mixture, beating constantly. Stir warmed egg mixture into lemon soup.
Add asparagus to soup and season to taste with salt and pepper. Heat lemon soup gently, but do not boil. Serve at once, sprinkled with parsley and grated lemon zest.