Boil a large pot of salted water, add orzo pasta, and cook according to package instructions (8-10 minutes). Drain and rinse under cold water to stop cooking.

Pat chicken breasts dry, brush with olive oil, season with salt and pepper. Grill over medium heat for 5-6 minutes per side until internal temperature reaches 165°F (75°C). Let rest before slicing.

In a mixing bowl, whisk together olive oil, red wine vinegar, lemon juice, Dijon mustard, honey, minced garlic, and a pinch of salt and pepper until well emulsified.

In a large bowl, combine cooled orzo, sliced chicken, diced avocado, halved tomatoes, diced onion, crumbled feta, and fresh herbs. Toss with dressing until well-coated.

Serve immediately or chill in the refrigerator for 20-30 minutes to enhance flavors.