Rinse the quinoa thoroughly under cold running water.
Add the quinoa and water to a medium saucepan.
Bring to a boil over medium-high heat.
Reduce the heat to low, cover, and simmer for about 15 minutes until the water is absorbed.
Remove from heat and let the quinoa rest uncovered for 5 minutes.
Fluff with a fork and allow it to cool completely.
Pit and halve the cherries.
Roughly chop the pistachios.
In a large mixing bowl, combine the cooled quinoa, cherries, pistachios, red onion, and chopped mint.
In a small bowl, whisk together the apple cider vinegar, lemon juice, salt, and pepper.
Pour the dressing over the salad.
Gently toss until everything is evenly coated.
Fold in baby arugula if using.
Taste and adjust seasoning as needed.
Serve immediately or chill before serving for an even more refreshing Cherry Pistachio Quinoa Salad.