If you can, first place the quinoa into a strainer and rinse under running water.
Put quinoa, water, and chicken base into a saucepan and bring to a boil. Cover and reduce to a simmer. Cook for 10 to 15 minutes or until all liquid is absorbed. Set aside to cool.
Combine lemon juice, vinegar, garlic, oil, and pepper in a bowl and set aside.
Combine cucumber, parsley, scallions, and red onion in a bowl.
When quinoa has cooled, stir in the feta cheese and dressing.