Soak the mushrooms in water for 30 minutes or until they are soft. Drain and shred finely. discard the tough stems.
Remove the skin from one of the lemons and shred it into strips the size of a matchstick. Finely grate the skin of the remaining lemon. Squeeze the juice from both lemons.
In a bowl combine the mushrooms, bamboo shoots, shredded and grated lemon skins, lemon juice, lemon extract, sugar, light soy sauce, chicken stock, and 1 tablespoon. of the dark soy sauce.
Split the chicken in half. Dry with paper towels and rub with the remaining dark soy sauce. Allow the chicken to stand for 10 minutes.
In a skillet heat the oil to 375 deg F and deep-fry the chicken for 5 minutes on each side. Cut the chicken into 1.5by 3 cm pieces and place them on a serving dish.
heat a wok or skillet over high heat until a drop of water immediately sizzles into steam. Add the peanut oil, salt, and gingerroot. Stir for about 30 seconds or until the gingerroot browns slightly. Lower heat to medium and add the lemon sauce mixture. Stir for 2 minutes to blend the flavors.
Add the chicken fat and stir for 1 minute. Add the cornstarch mixture to thicken the gravy, stirring constantly.
Pour the sauce over the chicken in the serving dish.