Rinse the quinoa under cold water to remove any bitterness. Drain well.

In a medium saucepan, bring 2 cups of water to a boil. Add the quinoa, reduce heat to low, cover, and simmer for 15 minutes or until the water is absorbed. Remove from heat and let it sit covered for 5 minutes. Fluff with a fork.

While the quinoa is cooking, prepare the vegetables. Dice the cucumber, halve the cherry tomatoes, and finely chop the red onion.

In a large bowl, combine the cooked quinoa, cucumber, tomatoes, red onion, feta cheese, and Kalamata olives.

In a small bowl, whisk together the olive oil, lemon juice, dried oregano, salt, and pepper.

Pour the dressing over the salad and toss gently to combine. Adjust seasoning if needed.

Serve immediately or refrigerate for at least 30 minutes to let the flavors meld together.