Make up the pancake batter by whisking together the mushrooms, flour, milk, egg, salt and baking powder.
Heat up a non-stick pan with a little butter. Pour in a ladleful of the mixture into the pan to create a 10cm wide pancake. Fit as many as you can in the pan. Cook gently on a low heat until bubbles form on the surface and the underside is golden. Flip until golden on the other side. Repeat until you finish the batter (about 8).
Top the pancakes with the pancetta and courgette mix, sprinkle with chilli flakes, hazelnuts and parsley. Serve immediately.