Stem and seed the guajillo chiles so they are flat. Heat a small skillet over medium heat. When hot add the chiles. Toast on each side until they are pliable and give off an aroma, about 1 minute per side.
Transfer the chiles to a bowl and cover with hot water. Allow to soak until soft, about 30 minutes. Transfer chiles to a mini-processor or food grinder with 1 tablespoon of the soaking liquid. Strain puree into a small bowl and discard the solid remains.
In a large skillet, heat the butter and olive oil. Salt and pepper the pork medallions. When butter stop foaming, add the pork tenderloin. Seat and cook them about 5 minutes per side.
Remove the meat from the pan to a warm plate.
Deglaze the skillet with the wine. Add the cream and chile puree and cook until reduced to the desired consistency. Stir in the chives.
Put the pork medallions back in the pan and cook until heated through. Place two medallion on each plate and spoon sauce over them.