Start to make the pancakes by pouring the 2 flour sorts in a bowl, add the egg and the salt and stir.
Add the water and the olive oil and stir it all together. Let the batter rest in the fridge for 1 hour.
Heat up a frying pan with some butter and pour 100 ml of the batter and fry it on both sides. Continue until all the batter are used.
Time to make the filling by cutting the mushrooms, celery and the shrimps in small pieces, and fry it in a frying pan together with the parsley.
Preheat the oven at 180 degrees Celsius.
Now it is time to make the sauce by melting the butter in a casserole, add the flour and stir together.
Add the milk, salt and pepper, and stir until it gets thicker.
Divide the filling evenly on the pancakes and roll them together. Place them in an oven form.
Pour the sauce over the pancakes and sprinkle the grated cheese as a last layer.
Place the pancakes in the oven for 20 minutes. Take them out and serve them warm.