Heat sesame oil in a large pot over medium heat. Add garlic and ginger, cooking for about 1 minute until fragrant (but don't let them burn!).
Pour in the vegetable broth and bring to a gentle simmer over medium-high heat.
While the broth heats, place miso paste in a small bowl and ladle in about ½ cup of the hot broth. Whisk until smooth and no lumps remain—this prevents the miso from clumping in your soup.
Reduce heat to medium-low and stir the miso mixture back into the pot along with the soy sauce.
Add the cubed tofu and greens to the pot. Simmer for 5-7 minutes until the greens are wilted and the tofu is heated through.
Remove from heat and stir in the sliced green onions. Taste and adjust seasoning if needed with more soy sauce or miso.
Ladle into bowls and top with dried seaweed if using. Serve immediately while hot and enjoy the instant calm that comes with each sip!