Bring broth to boil in a medium saucepan. Add quinoa, reduce to a simmer, and cover tightly. Simmer, covered, for 15 minutes. Remove from heat and let rest, covered for 10 minutes. Remove the lid and allow to cool to room temperature.

In another bowl combine the lemon juice and yogurt. Stir parsley, red onion, cucumbers, tomatoes and feta into the quinoa. Top with the yogurt mixture and mix until well combined. Season with salt and pepper. Serve at room temperature or slightly chilled.