Brown the sausage in a large skillet. Remove to a bowl and reserve.

Add olive oil to the drippings in the pan and saute the mushroom caps over medium heat until they have softened, but not collapsed. About 5 minutes or so.

Meanwhile, pulse the sausage, the reserved mushroom stems and a couple tablespoons cheese in a food processor. Season to taste. You want a filling that's fine enough to fit in the mushroom caps.

Fill the mushroom caps and return them to the skillet. Sprinkle more parmesan cheese over top each stuffed mushroom cap. Turn the heat to low and cover the pan with a lid until the cheese melts, about 2-3 minutes.

To serve, arrange on a platter and garnish with a little chopped parsley.