If the mushrooms are very large, cut in half; however it is traditional not to cut them in Thai cooking. Heat the oil in a wok over medium heat. Add the curry paste & stir-fry until it releases its aroma. Add 3 c water, mushrooms, soy sauce & sugar. Bring to a boil, adjust the seasonings if necessary. Add the basil, kaffir & chili peppers. Mix gently & serve hot with rice. Note: I make variations of this adding a bunch assorted, cubed vegetables which I stir-fry for a few moments before adding the water. Using the vegetables gives a main dish rather than just a side dish. Good vegetables in this curry are: eggplant, zucchini, corn, cauliflower, bamboo shoots (I'm not sure how Thai this ingredient is though).