Yesterday, I was in search of something light for lunch. Braised hijiki seemed like a good start, but I didn't have any abura-age on hand. What I did have was some sliced button mushrooms. I ended up using the normal recipe for braised hijiki, just substituting the mushrooms for the abura-age and sake for the mirin (I had some leftover sake, too).
This turned out to be such an easy and appropriate twist on the classic recipe that I'm almost embarrassed I didn't think of it before. Sliced button mushrooms, like abura-age, absorb liquids and concentrate flavors in sauces. Substituting sake for mirin made the sauce less sweet, which isn't always a bad thing. I poured everything over jasmine rice, which sopped up the sauce better than noodles would have done.