In a large mixing bowl, whisk together lemon juice and Dijon mustard until smooth. Gradually drizzle in olive oil while whisking to emulsify. Stir in red onion and dill, then season with salt and pepper. Set aside.

Bring a large pot of salted water to a rolling boil and add the orzo. Cook for 8-10 minutes until al dente, then drain thoroughly and toss in the dressing.

Add cucumbers, cherry tomatoes, chickpeas, and olives to the bowl with orzo and dressing. Gently toss until well mixed.

Crumble feta cheese over the salad and fold it in carefully.

Spoon individual portions into bowls and garnish with fresh dill. Chill for 30 minutes before serving.