Cook the Quinoa: First, rinse the quinoa thoroughly in a fine-mesh sieve under cold water. This removes its natural bitter coating, called saponin. Add the rinsed quinoa and the stock to a medium saucepan. Bring to a boil, then reduce the heat to low, cover, and simmer for 15 minutes, or until all the liquid has been absorbed.

Fluff and Cool: Once cooked, remove the quinoa from the heat and let it stand, still covered, for 5 minutes. Then, fluff it up with a fork and spread it out on a large baking tray to cool completely. This is my secret to preventing a clumpy, warm salad.

Prepare the Vegetables and Herbs: While the quinoa is cooking and cooling, get on with your chopping. Finely dice the cucumber and red onion. Roughly chop the toasted pistachios. Finely chop the parsley and mint. Drain and rinse the chickpeas. If you're adding protein, this is a great time to dice your cooked chicken.

Make the Dressing: In a small jar with a tight-fitting lid, combine all the dressing ingredients: extra virgin olive oil, lemon juice, tahini, Dijon mustard, minced garlic, salt, and pepper. Shake vigorously until the dressing is well-emulsified and creamy. I find that shaking it in a jar is much more effective than whisking.

Combine the Salad: In a large salad bowl, add the completely cooled quinoa, diced cucumber, red onion, chickpeas, and most of the pistachios, parsley, and mint (save a little of each for garnishing).

Add the Feta and Chicken: Gently crumble in the feta cheese and add the diced chicken, if using. Be careful not to over-mix at this stage, as you want to keep some nice chunks of feta.

Dress and Serve: Pour about two-thirds of the dressing over the salad and toss gently to combine. Have a taste and add more dressing, salt, or pepper if you feel it needs it. Serve immediately, garnished with the remaining fresh herbs and chopped pistachios.