Remove stems from mushrooms and using a spoon scoop out the gills from the caps. Place in a bowl with the soy sauce and water to "marinade" lightly about 10-15 minutes. *This helps them not to dry out when baking.
Preheat Oven to 375 degrees.
Mix hummus with the remaining ingredients and stuff into the mushroom caps.
Sprinkle the tops with a little extra panko, if desired.
Bake for 15 minutes.