Rub the fillet with salt and pepper and fry on all sides in the hot oil. Add shallots and fry with them. Brush the meat with mustard, add the wine and stew with the lid on for 10 minutes. Take out the meat and keep it warm.
Stir in the creme fraiche and season with salt, pepper and a pinch of sugar, simmer a little, then add the herbs to the sauce and season to taste again. Cut the meat into slices, distribute on 2 plates and cover with sauce.