In a saucepan bring water to a boil. Add rice and stir. Reduce heat, cover and simmer for 20 minutes.
Heat oil in a large skillet or wok. Add pork and onion and stir-fry until done and no pink is showing. Stir in tomatoes and steam until tomatoes are semi-soft. Remove from heat and stir in the cooked rice. Add the fish sauce and beaten egg and stir well;
the egg will thicken the mixture. Then it is Kal Pot and ready to serve!