Pre-heat grill. Cut the stems off the mushrooms. Put (face down) onto a tray and brush with oil. Cook for 5-10 mins. While the mushrooms are cooking mix together the grated cheese, chopped spring onion and garlic in a bowl. check your mushrooms. They should be brown on top. take out of the grill and turn right way up. grap a handful or two of your mixture and place on top of the mushroom. Put back into the oven for another 5-10 mins. Enjoy!