Rehydrate Kombu and Shiitake mushrooms in water for an hour.
Take Kombu and mushrooms out, saving the water. Cut Kombu into 1" squares, and slice mushrooms thinly.
Cook Kombu and Shiitake with 1 cup of the saved water at medium low heat for 20-25 minutes, covered.
Add the rest of the ingredients, and cook at low heat until all the liquid is almost gone. Check often so they don't burn.