Cook the quinoa: Bring quinoa and water (or broth) to a boil. Reduce heat, cover, and simmer for 15 minutes or until the quinoa is tender and the liquid is absorbed. Fluff with a fork and let cool.
Blanch the broccoli: Bring a pot of water to a boil. Add the broccoli and cook for 1-2 minutes until bright green. Drain and rinse with cold water to stop the cooking process.
Prepare the dressing: Whisk together olive oil, lemon juice, apple cider vinegar, honey, Dijon mustard, salt, and pepper.
Assemble the salad: In a large bowl, combine quinoa, broccoli, dried cranberries, sunflower seeds, feta cheese (if using), and red onion.
Toss with dressing: Pour the dressing over the salad and toss to coat evenly.
Serve and enjoy: Allow the flavors to meld for 10 minutes before serving. Enjoy chilled or at room temperature.