Heat the cooking oil to a medium heat. Slice the onions and add to the pan, and cook for about five minutes, until soft. Add the salt, vinegar, and sugar, and increase the heat slightly. Continue cooking until vinegar is absorbed, and onions are cooked through. Set aside until ready to assemble.
To make the nut seed mix
In a bowl, place the seeds and nuts and addthe lemon juice. Add the ras-el-hanout and cayenne, and toss to combine. Gently toast them in the oil in a medium-high frying pan until golden, stirring constantly, being careful not to let them burn. Set aside until ready.
To make the dressing
Whisk all dressing ingredients together until emulsified. Taste and adjust as necessary.
To make the salad, cook the rice and quinoa (see packet instructions). Place in a large bowl.
Add the salad greens, soft onions, herbs, and seeds. Gently toss, then add the dressing. Garnish with extra herbs.