Start by cooking the quinoa. First place the dry quinoa into a bowl and fill it with water. Stir with a spoon until the water becomes cloudy. Drain and rinse the quinoa using a mesh strainer.
Place the quinoa into a small pot with 2/3 cups of water or broth. Cover and bring to a bowl, then reduce to a low simmer and cook for 10 minutes until water is absorbed.
Set the quinoa aside for ten more minutes, and then fluff it with a fork. Cook the quinoa before using it in the salad. It's helpful to make the quinoa ahead of time.
Put the salad together: Divide the ingredients among the five mason jars. Start with the dressing, continue with tomatoes, cucumbers, chickpeas, quinoa, feta, eggs, and finish with the baby spinach.
Tightly place the lid on and store them in the refrigerator for up to 5 days.
When you're ready to eat, shake the jar and pour the salad onto a plate.