Clean the Portobello mushroom caps with a damp cloth, remove the stem and scrape out the gills so you have a well deep enough for the egg.
Rub a little bit of olive oil on the outside of the mushroom to help it cook and keep it from sticking to the pan.
Arrange the caps on a baking sheet.
Crack each egg into a small bowl and then carefully slide it onto a mushroom cap.
Sprinkle with black pepper and fresh herbs of choice, I used parsley but thyme would be great as well.
CAREFULLY place the baking pan into the pre-heated 375 degree F oven and bake for 20-30 minutes. The amount of time required depends on how thick your mushrooms are and how done you like your eggs.