Rinse the quinoa under cold water for at least 30 seconds using a fine mesh strainer. Drain well.
Combine the rinsed quinoa and water in a saucepan. Bring to a boil and decrease heat to maintain a gentle simmer. Cook uncovered until all of the water is absorbed, about 15 minutes.
Remove the pan from heat, cover, and steam the quinoa for about 5 minutes. Remove the lid and fluff the quinoa with a fork.
While the quinoa is cooking, dice the peppers, cucumbers, cherry tomatoes, and red onion. You can submerge the chopped red onions in cold water for about ten minutes to lessen the bite. Drain before adding to the salad.
Next, whisk all ingredients for the dressing together and set aside.
For a chilled salad place the quinoa in the refrigerator before mixing in the veggies and feta. You can also serve this salad at room temperature, but be sure to add the feta once the quinoa is fairly cool so the cheese doesn't melt.
Pour the dressing over the salad, toss and serve.
Top with sliced avocados or olives and add additional salt and pepper to your liking.