Rinse the quinoa in a fine-mesh sieve under cold water for a minute. This helps remove any bitter-tasting saponins.
In a medium saucepan, combine the rinsed quinoa with 2 cups of water or vegetable broth. Bring to a boil, then reduce heat to low, cover, and simmer for 15 minutes, or until all the liquid is absorbed and the quinoa is fluffy. Remove from heat and let it cool.
While the quinoa is cooking, prepare the vegetables. Dice the cucumber, tomatoes, and red onion. Roughly chop the fresh parsley and mint. If using Kalamata olives, pit them and halve them.
In a small bowl, whisk together the extra virgin olive oil, lemon juice, minced garlic, dried oregano, salt, and black pepper. Adjust the seasoning to taste.
In a large bowl, combine the cooked quinoa, diced cucumber, tomatoes, red onion, Kalamata olives, fresh parsley, and fresh mint.
Pour the lemon-herb dressing over the salad and toss gently to coat all the ingredients evenly.
Crumble the feta cheese over the salad. Serve immediately or chill in the refrigerator for later. The salad tastes even better after the flavors have had time to meld together.
