In a rice cooker, or pot over the stove, add two cups of dried quinoa with 3 1/2 cups water. Bring the mixture to a boil and then place a lid on the pan and turn the heat to low. Cook the quinoa until fork tender and you can fluff the quinoa. When it is cooked, remove it from the pan and set aside to cool. For the chicken, grill or bake the chicken until cooked through and no longer pink in the center. Season the chicken with salt, pepper, or lemon pepper. Let the chicken cool and cut into bite sized pieces. Slice the green onions, dice the bell peppers, dice the cucumbers and cut the grape tomatoes in half. Place the quinoa in a large bowl, add the cut up pieces of chicken and all of the vegetables. Sprinkle on top of the salad the feta cheese and the cut up mint leaves for garnish. For the dressing, combine all of the ingredients together in a blender or in a bowl with a whisk. Whisk until smooth. pour the dressing over the salad and toss, right before serving. Salad will stay good in the fridge for several days.