Properly rinse the porcini, and then put into salted water for 30 mins. Pull out, slice and cover with boiling water for a further 10-15 mins.
Peel, chop and fry onion in vegetable oil.
Put the porcini to onion, cook until ready. Sprinkle with salt and pepper.
Rinse and chop the parsley. Add 2-3 minced garlic cloves if you want the dish to be spicy.
Add the sour cream or cream to almost ready porcini, then reduce heat to minimum, and braise the porcini for little.
Set the finished porcini aside from heat, add the parsley. Serve hot.