Add the ginger, garlic, scallion, and 1/4 cup of the sesame oil to a small saucepan.
Place the saucepan over low heat and bring to a boil.
Gently simmer for about 3 minutes over low heat, or until the ingredients turn golden.
Gently swirl the pot while cooking to prevent the ingredients from burning.
Pour the oil into a mixing bowl.
Add the ichimi togarashi and coarse red pepper flakes, and mix to combine.
Allow the oil to come to room temperature, and then add the remaining 1/4 cup toasted sesame oil.
Transfer the rayu to a glass jar.
To use, spoon the red rayu oil from the surface (so the chopped ingredients remain resting on the bottom). You can also strain the rayu through a fine sieve to remove the chopped ingredients from the oil, before pouring it into a storage jar.