Bring a large pot of salted water to a rolling boil. Add orzo pasta and cook according to package instructions for 8-10 minutes until it's al dente. Drain the pasta in a colander and rinse with cold water to halt cooking.

While the orzo is cooking, prepare the chicken breasts by drizzling them with olive oil and seasoning with salt and pepper. Preheat your grill or grill pan over medium heat. Grill the chicken for about 5-6 minutes on each side until cooked through. Let the chicken rest for a few minutes before slicing.

In a small bowl, combine olive oil, vinegar, lemon juice, Dijon mustard, honey, minced garlic, salt, and pepper. Whisk the ingredients together until emulsified and creamy.

In a large mixing bowl, combine the cooked orzo, sliced grilled chicken, diced avocado, halved tomatoes, red onion, crumbled feta, and chopped fresh herbs. Pour the dressing over and gently toss until well-coated.

For the best flavor, cover and refrigerate the salad for 20-30 minutes. Serve immediately if short on time.