Rinse quinoa under cold water in a fine-mesh strainer. In a medium saucepan, combine with water. Bring to a boil, then lower heat to simmer for about 13 minutes. Fluff with a fork and cool in the fridge.

Heat a skillet over medium heat and toast walnuts and almonds (1/2 cup total) for 2-5 minutes until fragrant. Transfer to a plate to cool.

In a mason jar or bowl, combine olive oil, apple cider vinegar, Dijon mustard, honey, and season with salt and pepper. Shake or whisk until emulsified.

Finely chop broccoli and dice the apple. Toss in a large bowl, drizzle with lemon juice, and mix in cooled quinoa and feta cheese.

Pour dressing over salad mixture and toss gently. Add toasted nuts and mix well.

Serve chilled or at room temperature. Let sit for 10-15 minutes to meld flavors before serving.