In a pot over high heat, combine the water and quinoa. Bring to a boil, then reduce the heat and let it simmer for about 10 minutes until the quinoa is tender and cooked.

Remove the quinoa from the heat, keep it covered, and let it sit for 5 minutes.

Fluff the quinoa with a fork and allow it to cool completely.

In a bowl, whisk together the lemon juice, minced garlic, and black pepper. Gradually add the olive oil while whisking to create the dressing.

Add the cooled quinoa, cucumber, tomato, red onion, and parsley to the bowl. Pour the prepared dressing over the top and toss the salad well to combine.

Garnish with the feta cheese cubes and serve the salad chilled.