Rub the chicken parts with rock salt and set aside. (If you are going to use a whole chicken, rub it with salt in side and out then stuff with half the amount of ginger, lemon grass and onion then set aside.)
In a medium size pot, combine water, lemon grass, ginger, onion, salt and pepper. Bring to a boil then add the chicken. Simmer for about 35 minutes or until the chicken is tender. Turn off heat and let the it cool for a while. You will use the broth for the Hainanese rice later.
In the meantime, to make the Hainanese rice, in a wok, heat margarine and saute onion and garlic until fragrant. Wash the rice first then drain. Put the rice in the wok together with the onion and garlic and saute continuously for 5 minutes.
Then transfer the sauteed rice to the rice cooker and add the chicken broth. Cook until the rice is done.
To make the ginger dipping sauce, grate the ginger and put in a small bowl. Add the oil and salt. Mix thoroughly and set aside. In a separate bowl, put the soy sauce and kalamansi juice. Serve these dipping sauces with the Hannanese chicken. Garnish with green onions if desired.