Bring a large pot of salted water to a boil. Add the orzo pasta and cook for 8 to 10 minutes, stirring occasionally. Drain and rinse under cold water.

Preheat your grill to medium-high heat. Season the chicken with olive oil, salt, and pepper. Grill for 5 to 6 minutes on each side until cooked through. Let rest before slicing.

In a medium bowl, whisk together olive oil, vinegar, lemon juice, Dijon mustard, honey, garlic, salt, and pepper until emulsified.

In a large bowl, combine the cooked orzo, sliced chicken, diced avocado, tomatoes, red onion, feta, and herbs. Drizzle with dressing and toss to coat.

Serve immediately or chill in the refrigerator for 20 to 30 minutes before serving.