Rinse the quinoa under cold water in a fine mesh strainer to remove its bitter coating.
In a medium saucepan, combine the rinsed quinoa and water. Bring to a boil over medium-high heat.
Once boiling, reduce the heat to low, cover, and simmer for 15 minutes or until the quinoa is fluffy and the water is absorbed. Remove from heat and let it cool slightly.
In a large mixing bowl, combine the cherry tomatoes, cucumber, bell pepper, red onion, parsley, and feta cheese.
In a small bowl, whisk together the olive oil, red wine vinegar, lemon juice, oregano, salt, and pepper.
Add the cooled quinoa to the vegetable mixture and pour the dressing over it. Gently stir with a wooden spoon to combine everything well.
Adjust seasoning with more salt and pepper if needed. Serve chilled or at room temperature.