Cook the pasta as per package directions (put the quinoa in a medium pot with 2 cups of water. Bring to a boil, cover, and reduce heat to low. Simmer to cook, approximately 10-15 minutes, until the quinoa is soft but has texture like rice).
While the quinoa is cooking, cut the cucumber, onion, tomatoes, olives, and feta.
To make the dressing, in a small bowl combine the oil, vinegar, juice from 1/2 lemon, mustard, oregano, garlic powder, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Whisk to combine.
When everything is ready, add all ingredients and the dressing to the quinoa. Toss to coat and season to taste with salt and pepper.
Serve either immediately, or chill to serve cold. If desired, sprinkle some chopped fresh parsley on top right before serving.
Add more of any ingredient that you love, such as feta or cucumber.This will serve around 6 people as a side dish. Quinoa is very filling and goes further than the volume may appear it will.