Preheat the oven to 180 degrees C. Place the shortcrust pastry on a baking tray and cook for 10 minutes, cool down then cut 4 2x6 cm rectangles.
Clean the mushrooms then cut the stalk into rings. Add one tablespoon of butter into a frying pan and cook the stalks over high heat for 2 minutes. Add half of the stalks onto the pastry shell.
Cook the scallops with a teaspoon of butter in a frying pan over high heat for 2 minutes on each side. Slice one scallop and place it on top of the mushroom mixture on the mushroom tart. Cut the rest of the mushroom stalks finely.
Place the rest of the mushroom stalks on the filo sheet, roll and cut into 4 pieces of equal length. It will replace the stalk of the mushroom on your plate.
Put the 4 pieces in a frying pan with one teaspoon of butter over high heat for one minute. Remove then add the mushroom cups to the frying pan and cook for 2 minutes.
Puree the beetroot then pour into a fine sieve to extract the juice. Pour the juice into a saucepan and cook over medium low heat until reduced by half. Add a tablespoon of hazelnut oil.
Place the mushroom tart on the plate, 3 scallops, place the mushroom stalk made with the filo sheet under the mushroom cup, draw a line on the plate with the beetroot sauce.