In a wok over high heat, heat vegetable oil 2 to 3 min. Add sweet potato, reduce heat to medium-high and cook 8 to 10 min. until golden brown on all sides. Remove with slotted spoon and set aside. Working in the same oil, flash fry pork for 1 to 2 min. on all sides. Remove with a slotted spoon and set aside. Pour out ? of the oil. Add onions and saute until translucent, 2 to 3 min., stirring. Add garlic, cook for 1 min., stirring. Add carrots, red bell peppers, lemon juice and 4 Tbsp. curry powder. Mix thoroughly and cook for 2 to 3 min., stirring occasionally. Meanwhile, whisk coconut milk powder into vegetable stock until dissolved (or stir in coconut milk until blended). Return sweet potatoes, pork, remaining curry powder and stock mixture to the wok. Mix together thoroughly, raise heat to high and bring to a boil. Reduce to a simmer, stir in bamboo shoots and corn cobs. Cover and cook for 20 to 25 min., stirring occasionally.
Serve garnished with chopped cilantro.