Prepare quinoa according to the package directions. (It's usually a 2:1 water to quinoa ratio.) Let cool slightly or fully. You can do this step up to a day ahead.
Mix together the quinoa, chickpeas, cucumber, carrot, feta, and sunflower seeds in a large bowl.
To make the dressing, stir together the lemon zest and juice, olive oil, Dijon, oregano (if using), salt, and pepper. Toss into the salad and mix thoroughly. Serve or store for later.
Notes
Serve immediately or store in the fridge for up to 5 days.
Add strawberries, blueberries or sliced apples or pears to this salad if serving to kids if you think they might need more enticement to try it.
Serve the different ingredients next to each other if your kids prefer their food side-by-side.
Toss the salad well to ensure that the dressing coats the ingredients well.
Season to taste with salt to ensure that it's the right level for your own particular taste buds.