- Remove the stalks from the mushrooms and finely chop.
- Add the oil to a frying pan and brown the onion and chopped mushroom stalks for 4-5 minutes then allow to cool.
- Meanwhile, squeeze out any excess water from the spinach and place in a bowl.
- Mix the onion and spinach with plenty of pepper and the nutmeg. Stir in the cream cheese mix together well and form into 4 even-sized balls.
- Meanwhile, grill or griddle the gill-side (inside) of the mushrooms, then top each with the spinach mixture. Set aside until you are ready to grill or barbecue.
- Put the mushrooms onto the barbecue or griddle pan, loosely placing a piece of kitchen foil over the top, to trap the heat, allowing the smoky flavour to be absorbed. Cook for 4-5 minutes.
- Lightly toasted the bun and add the mushroom with lettuce, sliced tomato and red onion.
- You could cook the mushrooms in a medium oven for 10-15 minutes instead on the barbecue.
- Try making mini versions using smaller mushrooms and buns, they're great for a party.