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.
Fresh ginger drives the aromatic profile here, requiring careful heat management to prevent the minced root and garlic from scorching in the sesame oil before the ground pork renders its fat. Testing this sequence reveals specific pitfalls regarding water release from squash and greens.
Brown the pork over medium-high heat until the meat develops distinct crusty bits, which provides the foundational depth for the chicken broth.
Add the zucchini noodles in the final three to five minutes of boiling; overcooking turns the squash into mush and releases excess water into the soup.
Separate the white scallion bases for sautéing with the ginger while keeping the green tops raw for a crisp garnish.
Store leftovers in an airtight container for up to two days, noting that zucchini will soften further upon refrigeration and should be reheated gently without boiling.
Freezing is not recommended because thawed zucchini loses its structural integrity completely and turns the broth watery.