Preheat the oven to 425 degrees F. In a large saucepan, combine the orange juice, Grand Marnier, ginger, orange zest, stock, sugar and star anise. Bring to a boil, reduce to a simmer and simmer until reduced by half. Season with salt and pepper. Remove from the heat, remove the star anise and cool. Separate the glaze into 2 containers. Score the skin of the duck breasts in a diamond pattern with a sharp knife. Season the duck with salt and pepper. Place the duck breasts, skin side up, in a large baking dish. Place the duck in the oven and roast for 10 minutes. Remove the duck from the oven. Lower the temperature of the oven to 375 degrees. Using 1 of the containers of the glaze, brush the dusk breasts generously with the glaze. Return the duck to the oven and bake for another 5 to 10 minutes to cook the duck to a medium rare. Remove the duck from the oven and place the breasts on a large platter. Heat up the second container of mandarin glaze in a small saucepan. Add 2 tablespoons of the pan drippings and cook for 5 minutes. Remove from the heat and brush onto the duck breasts. Serve with vermicelli and spring vegetables.