Preheat the oven to 200 °.
First fry the meat well on all sides in a heat-resistant saucepan in clarified butter. Add the carrots and onions, fry a little more and brown. Pour in water and put the pot with the lid in the oven for 45 - 55 minutes.
In the meantime, brush the defrosted frozen puff pastry pieces individually with melted butter and glue them together to form a whole. Is not necessary with a fresh puff pastry roll, provided it is large enough to wrap the meat. Roll out the puff pastry block again thinly, 3 times as large as the meat will be afterwards.
If the meat is very thick, cut it once in the middle so that you have two smaller pieces of equal size. Then place the meat in the middle of the dough and cover it completely. Straighten the sides and press firmly together with a fork.
Now place the seam side down on a baking sheet lined with baking paper and bake in the oven for another 45 - 50 minutes. The puff pastry should have turned a golden brown color.
Then take the meat out of the stock and let it drain a little. Pour the brew through a sieve. Keep the carrots and onions and the gravy separately.
Make a sauce from the gravy later by adding ice-cold butter and adding salt and pepper to taste.