Rinse quinoa under cold water. In a medium saucepan, combine quinoa and water. Bring to a boil, then reduce heat, cover, and simmer for 15 minutes. Remove from heat and let stand, covered, for 5 minutes. Fluff with a fork and let cool.

While quinoa cools, chop the tomatoes, cucumber, onion, olives, and parsley.

In a large bowl, combine cooled quinoa, veggies, feta, and olives.

Drizzle with olive oil and lemon juice. Sprinkle with salt and pepper. Toss everything together until well mixed.

Taste and adjust seasoning if needed. Serve chilled or at room temperature.