In a large soup pot, heat 1 teaspoon sesame oil over medium heat. Add garlic and ginger, sauté for 1–2 minutes until fragrant.
Pour in chicken or vegetable broth, stir in soy sauce, and bring to a gentle simmer. Taste and adjust seasoning if needed.
Add sliced mushrooms to the broth and simmer for 3–5 minutes until softened.
Drop frozen dumplings into the simmering broth. Cook for 6–8 minutes, stirring gently to avoid sticking.
Add chopped bok choy and most of the scallions. Simmer for 1–2 minutes until the greens are tender.
Ladle soup into bowls and garnish with sesame seeds, red pepper flakes, and the reserved scallions.
