Place the quinoa and 1 3/4 cups of water in a medium-size saucepan and bring to a boil over high heat. Cover, lower the heat to a simmer, and cook for 15 minutes, or until all the water has been absorbed. Allow to sit, covered, off the heat for at least 10 minutes, but longer, if possible. Transfer to a serving bowl and fluff with a fork. Set aside to cool.
Add the arugula, cherries, celery, parsley, almonds, and pecorino, if using, to the quinoa.
Prepare the dressing: combine all the dressing ingredients in a screw-top jar and shake until emulsified or whisk in a bowl.
Pour enough dressing over the salad to coat everything lightly. Add more as needed.
Notes
Toast almonds in a skillet with a smidge of olive oil and a pinch of salt. For a nut-free option, use toasted sunflower seeds.