Cook orzo according to package instructions which is same as any other pasta. Bring a pot of water to boil, add orzo and boil for 7~9 minutes. Drain and set aside.
In the meantime, whisk olive oil, mustard, vinegar, salt and pepper in a small bowl.
To the cooked orzo, add chopped artichokes, olives, tomatoes, green onions, dill, parsley and the dressing. Toss, taste and adjust the seasoning. Sprinkle with feta cheese and serve.