Preheat the oven to 350Â°F. Pierce the sweet potatoes with a fork and bake until tender, 30 to 40 minutes. While theyâ€™re baking, make the sauce. In a saucepan over medium-low heat, combine the orange juice, water, ginger, miso, soy sauce, garlic, and brown sugar. Cook until the sauce reduces and is thick enough to coat the back of a spoon, about 15 minutes. Set aside.
When the sweet potatoes are cool enough to touch, slice them in half lengthwise and lay them face up on a sheet pan. Spoon the sauce over the flesh of the potatoes, sprinkle with the sesame seeds, and broil until the sesame seeds are toasted.
Edited: October 15th, 2009