Place a medium pot over medium-high heat and add in the sesame oil. Once oil heats, add in the pork, breaking it up in the pan. Once broken, add in the garlic, ginger, the whites of the scallions and red pepper flakes. Season with salt and cook until browned. When the pork is just about browned. Add in the chicken broth, bok choy, soy sauce, fish sauce and bring to a boil. Then, add in the zucchini noodles and mushrooms and let cook for 3-5 minutes or until the noodles are cooked to your preference.Meanwhile, place the corn in a small pot and cover with water and a pinch of salt. Bring to a boil. Once boiling, cook until fork-tender, about 2-3 minutes. Drain into a colander and shave the kernels off with a knife and set aside.Divide soup into four bowls and top with corn and remaining scallions.