Amounts are approximate. Preparation time includes marinating. Fresh scallops from a reputable fishmonger are best but if you freeze them yourself, they're good for a couple of months. As for mushrooms, I like to use a variety, say portobellos, shitake (remove stems), and/or oyster, depending on availability. If large, break them up to bite size or less.
Slice the largest scallops in half. Marinate all ingredients together except the bok choy for one hour.
Preheat oven to 350 degrees F.
Chop the bok choy up roughly and mix in with the rest of the ingredients. Put everything into a baking dish so that it covers the bottom, but roughly not more than a layer and a half.
Bake 15-20 minutes, and serve, using a slotted spoon if there is too much moisture.