This salad is so, so, SO pretty, and a cool example of how quinoa can play a supporting role in a salad. The play of leafy greens against the quinoa, punctuated by the tart chewiness of the dried apricots, the bite of the onion and the tanginess of the dressing, makes for a very exciting salad.
Heat 2 teaspoons of the olive oil in a medium saucepan over medium heat, then add the quinoa and cook, stirring frequently, for 2 minutes. Add the broth. Bring to a simmer over high heat, then reduce the heat to medium low and simmer, covered, for 15 to 18 minutes, until all of the water is absorbed.
Spread the cooked quinoa out on a rimmed baking sheet to cool. In a small bowl or container, combine the lemon juice and remaining 2 tablespoons olive oil; season with salt and pepper.
In a large serving bowl, mix together the spinach, apricots, onion and parsley if using and toss with the dressing. Lightly toss in the cooled quinoa. Sprinkle with the cheese and serve.