In the bottom of a soup pot, heat the sesame oil on medium-high. Add the garlic, mushrooms, and ginger, and saute until the mushrooms soften, about 4 minutes.
Add all of the remaining ingredients, except the lemon juice and cilantro. Cook, uncovered and stirring occasionally, for 10 minutes.
Remove the pan from the heat, and add the lemon juice. Top each bowl with about a tablespoon of cilantro, if you're using it, and serve right away.