In a large bowl, combine the cooked quinoa, sliced kale, blueberries, walnuts, and crumbled feta cheese (if using). Toss gently to mix.
In a separate small bowl, whisk together the olive oil, lemon juice, honey (or maple syrup), Dijon mustard, salt, and pepper until well combined.
Drizzle the dressing over the salad and toss until everything is evenly coated.
Let the salad sit for a few minutes to allow the flavors to meld together.
Serve the superfood quinoa salad as a refreshing and nutritious main course or as a side dish. Enjoy!