Here's an idea for a delicious appetizer using portobello mushrooms. The caps of the portobello mushroom are very suitable for holding delicious ingredients in place.
For this particular appetizer, take shrimp, carrots, scallions, onions and garlic and puree them all in a blender. Season the resulting puree with salt and pepper. Now, in order to determine if the seasoning is enough, you would need to cook a bit of the puree in oil and taste it. Repeat this step until you are satisfied with the seasoning. Next, you need to clean the portobello mushroom caps by removing the gills with a spoon. After doing that, you can now take some of that puree and slather it on the cap, essentially using the cap as an edible container.
Cook the mushroom with the puree by baking it in an oven at 420F. Brush some melted butter on top of the puree and add some water to the pan that holds the appetizers. This is to prevent the mushroom caps from drying out. Bake for approximately 30 minutes and you will have yourself some yummy mushroom and shrimp appetizers as pictured above.
Enjoy!