Roast all solid spices in a pan without oil or fat over a mild heat and then grind finely in a mortar. Add the ground spices and strain them through a tea strainer.
Rub the prepared meat on all sides with the spice mixture, place on a correspondingly large piece of baking paper, roll up like a candy. Fold over the ends and fix (tie) with kitchen thread.
Place the meat on a wire rack and cook on the middle rack at 80 ° C for about 120 minutes. Now take out the meat, unpack it and fry it all over in hot clarified butter (over medium heat). Put the meat back on the wire rack, now uncovered at 90 ° C and let rest for another 30 minutes.
Cut the roast across the grain and arrange on preheated plates. Now season with salt, garnish if necessary and serve immediately.
Note: The cold, thinly sliced roast is very suitable as an accompaniment to an appetizer or as a topping on bread!