Lightly toasting the cut sides
of burger buns gives just a little
crunch and stops them going soggy.
Heat grill to high. Rub the mushrooms with oil; set on a baking sheet. Grill for 3 mins on each side until cooked, but still firm. Mix the cheese, garlic, butter and seasoning in a bowl, then spoon into the mushrooms. Grill until the cheese melts, then stuff into toasted buns with salad.