In a large pot of boiling water, cook the brown rice, wild rice and barley for 40-45 minutes, until tender. Drain well and run under cool water to stop the grains from cooking. Transfer to a bowl and add the chick peas and raisins.
Whisk together all the dressing ingredients (adjusting them if you like to suit your taste) and pour over top. Chill in the fridge until the mixture is completely cool, or for up to a day.
Add the tomatoes, green onions, parsley and pecans (or save them to sprinkle on top) and serve. Serves 4-8, depending on whether you're eating it as a main course or side dish. (It would go really well beside a filet of salmon.).