Rinse the quinoa under cold water in a fine-mesh sieve. Turn it out into a large microwave-safe bowl and add the water. Cover and microwave on high for 9 minutes. Set aside for 2 minutes and then carefully uncover and fluff with a fork. The quinoa should have a tender snap when you bite it - if it doesn't, cover and microwave for up to 1 minute longer.
Stir the parsley, cilantro, mint, tomatoes, and scallions into the quinoa. Whisk the lemon zest and juice with the olive oil, salt, and pepper in a small bowl to make a vinaigrette and pour it over the quinoa. Cover the bowl with plastic wrap and set aside at room temperature for 1 hour for the flavors to combine before serving.
Reprinted from the book Ten Dollar Dinners. Copyright (c) 2012 by Melissa d'Arabian. Published by Clarkson Potter, a division of Random House, Inc.