Cut tofu crosswise into pieces the shape of French-fried potatoes. Heat a wok, coat with oil & sprinkle on the salt. Add onion, then the mushrooms, stir frying each over high heat for about 30 seconds. Reduce heat to medium-low. Add carrot, green pepper & tofu in that order, sauteeing each for about 1 minute. Reduce heat to low & add sake, soy sauce, ginger, sugar & water. Simmer for 3 to 4 minutes. Stir in dissolved cornstarch & simmer 30 seconds for another 30 seconds. Shurtleff & Aoyagi, "The Book of Tofu"