Umami rich and sticky sweet, dengaku sauce is best known in recent times as a glaze for grilled eggplant. Dengaku can be used to glaze anything you like, from vegetables to proteins.
The etymology of dengaku is uncommonly cute. At festivals, grilled tofu was (and is) topped with the sauce with a skewer inserted into the white block — this is said to resemble a white-robed performer known as a dengakuhōshi, who performed acrobatics balanced atop a single bamboo pole (a mimic of ancient rice planting technique).
Usually, dengaku sauce is boiled before application. The starches in the beans and rice kōji (Aspergillus oryzae) that make up the miso thicken along with the addition of extra sugar in sweet mirin (unpasteurized kōji miso will be most active in terms of enzymes and have best results). These same parts make a delicious marinade that can be eaten as is or cooked afterward. For a more savory marinade, the extra sugar can be omitted.