Heat one tablespoon of the stock in 4 to 5 quart Dutch oven of stock pot over medium. When it begins to sizzle, add the onions, leeks,carrots,and celery. Saut until the vegetables are soft, about six minutes. Stir in the ginger, lemongrass, and garlic, and heat until aromatic. Sprinkle the turmeric over the vegetables and stir.