Blacken the pepper, either over a chimney starter or directly on the flavourizer bars.
Place the pepper into a resalable bag and allow to sweat for 10 minutes.
Place the pancetta on a stainless tray and grill over direct heat for 2 minutes. Remove from the tray and allow to cool.
Peel the blackened skin off the pepper and chop into small cubes.
Finely chop the crispy pancetta and in a bowl mix together half of the pancetta, pepper and cream cheese.
Divide the stuffing between the 6 mushrooms and sprinkle with the remaining pancetta.
Set up the barbecue for roasting, indirect. Place the mushrooms onto a soaked wood plank and then place in the centre of the cooking grate for 10-15 minutes.