Pre heat oven to 180 C
Brush one sheet of philo pastry with melted butter, remove the thyme leaves from the sprig and sprinkle over the philo with 20g of the grated parmesan.
Place the other sheet of philo on top and run your hand over the top to dispel any air that may be trapped. Brush this top sheet with the remaining butter.
Cut out a large round using a pastry cutter or cut round a saucer.
Place the round in between two silpat mats and bake for exactly 8 minutes.
Remove the crispy rounds and place on a wire rack to cool.
Pick out one perfectly shaped cep for roasting and presentation.
Cut the remaining cepes into 3mm dice keeping all the trimming to one side.
Finely slice the button mushrooms.
Melt 50g of the butter in a small saucepan, add the cep trimming and the button mushrooms, season with a little salt and the lemon juice, cover with a lid. Cook gently over a medium heat till mushrooms are completely soft.
Blend till a very smooth puree and keep till needed.
Melt another 50g of butter in a saucepan, add the chopped shallots and crushed garlic, sprinkle with a little salt and cook gently for 4 minutes.
Add the diced cepes turn the heat up a little and cook till the ceps just begin to take colour. Add the stock and cream and boil till almost evaporated. Remove from the heat till needed.
Heat a small frying pan with a little vegetable oil.
Season the sweetbread and fry over a medium heat till golden brown, add the whole cep and continue to cook till both are nicely caramelized. Add the remaining butter and baste continuously till sweetbread and cep are cooked.
Remove from the pan and drain on a cloth.
To Finish
Put the philo disc into the oven to re heat.
Warm the diced cep mixture, when hot fold in the mushroom puree and the grated parmesan. Check the seasoning and add the chopped tarragon.
Place the warmed disc onto a tray, place a cutter slightly smaller than the disc onto the disc and press the mushroom mixture into the cutter and smooth with the back of a spoon.
Place the mushroom tart onto the centre of a warmed plate, place the caramelized cep and sweetbread on top and garnish with a piece of flat parsley.
Drizzle a little Madeira sauce around and serve immediately