In a large mixing bowl, whisk together lemon juice and Dijon mustard. Gradually drizzle in olive oil while continuously whisking. Add dill and red onion, followed by salt and pepper. Set aside.

Bring a pot of salted water to a boil and add orzo. Cook according to package directions until tender yet al dente, usually about 8-10 minutes. Drain and add to dressing immediately.

Stir in cucumbers, cherry tomatoes, and chickpeas with the orzo-dressing mixture. Toss gently to coat. Fold in crumbled feta cheese carefully.

Divide salad into bowls or a serving dish. Garnish with additional dill. Serve immediately or refrigerate for 30 minutes to chill.