Start by pre-heating a griddle pan in Roccbox, rubbing your bread with a good lug of olive oil and toasting in the hot griddle pan, flipping halfway through for around 2 minutes.
Rub the hot toast with the raw garlic and pop on a plate.
Pre heat a new pan in Roccbox, add a little olive oil and allow that to get hot too before adding your mushrooms. Squeeze over the lemon juice and season well.
Cook the mushrooms in Roccbox for around 90 seconds before adding your walnuts and cooking for a further 30-60 seconds.
Working quickly, remove the pan from Roccbox and add the water to the pan. Tilt the pan so the liquid sits at the top and gradually add the butter, mixing continuously as you do so until a shiny sauce is achieved.
Add the chopped parsley and truffle oil, pour the mushrooms and sauce onto the toast before topping with grated parmesan.