
This Chinese-style button mushroom soup is light, savory, and full of deep mushroom flavor from a simple pan-searing technique. With soy sauce, fresh cilantro, and scallions, it comes together quickly for a comforting bowl that tastes far richer than its short ingredient list suggests.
Clean the button mushrooms well and pat them completely dry. Remove the stems from the caps, keeping both parts for the soup.
Heat a medium soup pot over medium-high heat until hot. Add the vegetable oil, then arrange the mushroom caps in a single layer with the hollow sides facing up. Add the stems around them.
Lower the heat to medium and let the mushrooms cook undisturbed until the caps are browned and their natural juices collect inside, about 5 to 7 minutes. Check that the stems are browning as well, but avoid stirring too early so the mushrooms develop a deeper flavor.
Pour in the water and light soy sauce. Bring the soup to a boil, then cover, reduce the heat to medium-low, and simmer for 5 minutes.
Taste and season with salt as needed. If using the cornstarch, mix it with a small amount of cold water until smooth, then stir the slurry into the soup and simmer for about 30 seconds, just until lightly thickened.
Turn off the heat and stir in the cilantro and sliced scallion just before serving. Ladle the soup into bowls while hot.
Dry the mushrooms thoroughly before searing so they brown instead of steaming. For a thinner, clearer soup, skip the cornstarch slurry; for a thicker texture, add it gradually and stop once the broth lightly coats the spoon. Store leftovers in an airtight container in the refrigerator for up to 2 days and reheat gently on the stovetop.




