Heat the oil in a large pot over medium heat, until shimmering. Add the garlic and ginger, and cook for a few minutes until softened. Add the soy sauce and mirin, and stir to combine. Cook for another minute. Add the stock, cover, and bring to boil. Remove the lid, and let simmer uncovered for 5 minutes, then add the mushrooms. Simmer gently for another 10-15 minutes, and season with salt, to taste

.Make the soft-boiled eggs: Fill a pot with enough water to cover the eggs, and bring to a boil. Gently lower the eggs (still cold from the fridge) into the boiling water, and let simmer for 7 minutes (for a slightly runny yolk) or 8 minutes (for a soft, but set-up yolk).

Meanwhile, fill a large bowl with ice water. When the timer finishes, transfer the eggs to the ice bath to stop the cooking process. Wait at least 5 minutes, or until cool enough to handle, then carefully peel away the shell and set aside until ready to serve.

Cook noodles according to package rinse with cool water after cooked to stop further cooking.

Build bowls by layers - noodles, chicken, broth, egg (sliced lengthwise over your bowl), top with scallions and enjoy!