Actually I really love these mushrooms and kindly use the caps only and toss the woody stems aside. Unlike any other mushroom, the caps have a pleasent and meaty flavor while the stems are pure rubbish. The stems of this perticular mushroom can be tossed in to the compost heap if you wish.
The caps you can season it any old way you choose. You will need 4 caps only and season it with salt or other types of seasonings especially herbs, 3 dashes of any type of vinegar 3 tbs of any type of cooking oil you prefer. Just use one type only of your choosing and it depends on your taste so you decide. Add 3 dashes of worchestershire sauce. Grind 1 pinch of peppercorns of your choosing, crush 2 cloves of garlic and add to the caps then add the oil to either a grill pan you place on stovetop or grill it on your grill.
For electric grills it is 4. Grill until you see the grill marks forming. Take 1 onion and add more oil to the pan and fry them until they are brown. Also you can add 3 pats of butter instead of cooking oil if you prefer too. Serve these portobello burgers with melted cheese on top if you perfer and serve with the grilled onions and a salad.

