Combine dashi, light miso and barley miso in a large saucepan and blend with a hand blender.
Bring to a simmer over medium-high heat and add manilla clams. Allow cooking for about a minute.
Add cubed tofu and sliced scallions.
Allow to warm through and serve.
Basic Dashi
In a medium-sized stockpot over high heat bring the kombu, shiitake, and water to 140 degrees Fahrenheit and hold that temperature steady for one hour.
Remove shiitake and kombu and reserve for pickles.
Add bonito flakes and simmer for about 5 minutes.
Strain through a fine strainer, pressing solids to get maximum flavor.
