Preheat the oven to 180°C.
Roll the pastry into a rectangle 2mm thick to accommodate twelve 7.5cm circles.
Place pastry on a sheet, prick with a fork, season, and weight with a second sheet.
Bake for 20 minutes until golden-brown and leave to cool.
Fry shallots and chestnut mushrooms in butter and season with tarragon, salt, and pepper.
Add Madeira and cream, then simmer until reduced by a third.
Blend the mixture into a mousse and transfer to a piping bag.
Sauté girolles in butter for 3 minutes and finish with lemon juice.
Cut twelve 7.5cm pastry circles using a cutter.
Stack three pastry circles per serving, piping mousse between layers.
Garnish the top layer with girolles and chopped chives.