Bring a large pot of salted water to a boil and cook the chickpea pasta according to package directions for al dente texture.
Drain the pasta and immediately rinse with cold water to stop the cooking process; drain thoroughly.
In a small mixing bowl, whisk together the Greek yogurt, ranch seasoning, lemon juice, and milk until a creamy consistency is achieved.
In a large salad bowl, combine the chilled pasta, diced chicken, cherry tomatoes, cucumber, red onion, and spinach.
Pour the yogurt ranch dressing over the pasta mixture and toss gently to ensure even coating.
Season with salt and black pepper to taste.
Cover and refrigerate for at least 30 minutes before serving to allow the flavors to meld.