Begin by boiling a large pot of salted water. Add pasta and cook until al dente, typically around 8-10 minutes. Drain and rinse under cold water.

In a medium bowl, whisk together olive oil, lemon juice, Greek yogurt, Dijon mustard, garlic powder, salt, and pepper until smooth. Set aside.

In a large mixing bowl, combine cooled pasta, chicken, chickpeas, and edamame or peas. Add tomatoes, cucumber, and onion. Fold in feta and sunflower seeds if using.

Pour the dressing over the salad and toss gently to coat all ingredients. Maintain the texture of vegetables.

Cover and refrigerate for at least 30 minutes to allow flavors to meld. Garnish with parsley or basil before serving.

Serve chilled as a main dish or hearty side.