Instructions

1. Place the broth, ginger, and garlic in a large saucepan and bring to a boil over high heat. Reduce the heat to medium-low and simmer until fragrant, about 10 minutes. Meanwhile, cook the mushrooms.
2. Melt 1 tablespoon of the butter in a large skillet over medium heat. Add the mushrooms in a single layer (it’s okay if a few overlap) and cook undisturbed until browned, about 5 minutes. Add the tamari, 2 tablespoons of the miso, and remaining 1 tablespoon butter and toss, breaking up the miso with a spoon, until evenly dispersed and the butter is melted. Continue cooking until mushrooms are tender and are deeply browned all over, 4 to 5 minutes more. Remove from heat and set aside.
3. Remove and discard the ginger and garlic from the soup. Remove a ladleful of broth from the pot and transfer to a small bowl or liquid measuring cup; set aside. Return the remaining broth back to a boil. Add the eggs (it's okay if eggs aren't completely submerged) and cook 6 to 8 minutes (6 for the runniest yolks, 8 for slightly firmer yolks). Remove the eggs with a slotted spoon; run under cold water until cool to the touch; peel and set aside. (Alternatively, plunge into an ice bath).
4. Return the broth to a boil. Add the soba and edamame and cook until both are tender, 3 to 4 minutes. Remove from the heat. Whisk the remaining 1 tablespoon miso into the reserved ladleful of broth until smooth. Add to the pot and stir to combine.
5. Divide the broth, noodles, and edamame between 4 bowls; top with the mushrooms. Slice the eggs in half lengthwise and add to the bowls. Garnish with togarashi and scallions, if desired.