These are soooo yummy!
In the AM scrape the gills out of the mushrooms w/ a spoon and remove the stems. Wipe them down w/ a damp paper towel to remove any dirt or gill remnants. Dot them w/ soy sauce and let them sit in the fridge all day while you are super busy at work.
When you get home from work preheat the oven to 350 and take some peeled shrimps and sautee them in a little bit of olive oil w/ oregano, pepper, rosemary, and basil. When the shrimp are done cut them in half in the pan. Leave everything in the pan but turn off the eye!
I used frozen spinach that had been defrosted but I'm sure you could use fresh. If you use frozen remove as much of the water as possible and add one box to the pan w/ the shrimp. Crumble a log of goat cheese into the pan and add sundried tomatos to taste. Stir the mixture until decently blended. Then add it in heaping spoonfuls to your yummy mushrooms. I found that using a lb of shrimp, box of spin, and one log of cheese was enough for four portobellos. Bake them on a cookie sheet lined w/ aluminum foil at 350 for about 35 mins or until the mushrooms feel tender. If they seem to be burning on the top you can sprinkle them w/ parmesan cheese about halfway through.
I used low fat goat cheese and parm to make it better. I'm sure you could add chopped mushrooms, a little onion, or some garlic or whatever makes things taste yummy for you.