Pre heat oven to fan forced 190ºC. Line large shallow rectangular baking tray with baking paper and then lay pastry across tray, with ends coming up over the trays edge. Join pastry in centre by pushing together.
Lay fillings (spinach, bacon and mushrooms) across prepared base starting with spinach.
Place cheeses and rosemary into thermomix bowl and mill for 10 seconds on speed 8. Set aside.
Place remaining ingredients into thermomix bowl with half the cheese and mix for 8 seconds on speed 6. Pour over fillings making sure not to over fill.
Top with remaining cheese and bake for 20-25 minutes until puffy and golden.