Remove the noodles from the refrigerator to bring to room temperature. Wash and dry the fresh produce. Thinly slice the mushrooms. Thinly slice the scallions, separating the white bottoms and hollow green tops. In a bowl, whisk together the miso paste and 1/4 cup of hot water until smooth.

Using your hands, carefully separate the noodles. In a medium pot, heat the sesame oil on medium-high until hot. Add the sliced mushrooms and sliced white bottoms of the scallions. Cook, without stirring, 4 to 5 minutes, or until browned. Add the sautéed aromatics and soy sauce. Cook, stirring frequently, 30 seconds to 1 minute, or until combined. Carefully add the miso mixture, broth, and 1 cup of water. Heat to boiling on high. Once boiling, reduce the heat to medium-low. Add the noodles. Cook, stirring frequently, 1 to 2 minutes, or until combined and heated through. Turn off the heat. Taste, then season with salt and pepper if desired. Serve the soup topped with the crispy onions, furikake, and sliced green tops of the scallions. Enjoy!