Thoroughly rinse the quinoa and steel-cut oats under cold running water to remove any bitterness from the quinoa’s outer coating. This step is essential for achieving a clean, nutty flavor.
In a large skillet with a lid, heat the olive oil over medium heat. Add the rinsed quinoa and steel-cut oats, stirring frequently, and toast them for 2–3 minutes until they develop a slight golden color and a warm, nutty aroma.
Pour in the water or broth, then bring the mixture to a rolling boil. Once boiling, cover the skillet, reduce the heat to low, and allow it to simmer gently for 15 minutes until all the liquid is absorbed. Turn off the heat, keep the lid on, and let the grains sit undisturbed for another 15 minutes to complete the cooking process. This resting period ensures a light, fluffy texture.
While waiting for the grains to cool, chop the cucumber, red onion, parsley, and mint. Prepare the pistachios and feta cheese.
Once the quinoa and oats have slightly cooled, fluff them with a fork and transfer them to a large mixing bowl. If they are still very warm, allow them to rest for an additional 5–10 minutes before adding the herbs to prevent them from wilting.
Stir in the chickpeas, cucumber, red onion, pistachios, feta cheese, parsley, and mint. Drizzle the lemon juice and olive oil over the mixture, then season with salt and freshly ground black pepper to taste. Toss gently until everything is evenly combined.
This salad can be enjoyed immediately or left to chill in the refrigerator for a few hours to allow the flavors to meld beautifully. Serve cold or at room temperature for a refreshing and wholesome dish.