Season the medallions with salt and black pepper.
Grease a thick-bottomed pan with olive oil, turn on the heat and when the pan is hot, place the fillets.
Grill the fillets on both sides and set aside.
In a food processor, place the boiled potato, Brazil nut oil, chestnuts and warm water.
Beat until it forms a smooth and homogeneous cream.
Adjust the salt and return to the pan to heat.
