recipe idea - egg baked in a portobella?

Seeing the egg tarts in the One Perfect Thing thread, I had an inspiration for an egg baked into the cup of a portobella mushroom. Usually, I go the other way around, with mushrooms folded into my scrambled eggs.

Has anyone had something like this? I'm thinking I'd need to at least par-roast the fungus to keep the moisture level down in the cap and so that it isn't raw when the egg is done, or the egg cooked long past hard. Ideally this could serve as a low-carb Benedict, perhaps with a slice of ham between the shroom and egg (or crumbled cooked sausage?). Topping it is left as an exercise for the reader/writer.

Now I'm thinking quail eggs in criminis as finger food...

Sounds like a nice idea, but I'd roast the portobella by itself and top it with a poached egg. Cooking them together runs too much of a risk of ruining the egg yolk.

Best,
Michael