The most suitable cut:

The most suitable cuts are fillet steak, beef tenderloin or filet mignon, which in Italy are simply translated as beef fillet.

The main difference between beef tenderloin and filet mignon is that the tenderloin is the long part of the meat running along both sides of the animal’s spine. The filet mignon, on the other hand, is slightly more tender than the rest; its tenderness is almost indistinguishable.

The filet mignon usually comes as a round cut taken from the narrower end of a tenderloin piece.

It is often the most tender and lean cut.

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You can choose to make the puff pastry yourself following the recipe here, or buy it ready-made. To apply diamond cuts, a sharp knife is needed.