Cut the tenderloin into slices. Sprinkle with salt, pepper, Provencal herbs and rub with half of the garlic and leave for an hour to marinate. While the meat is marinating, prepare the leek. It's time to cut the white part into slices. In a frying pan, melt half the butter. Put the chopped leek on the hot butter and fry it for a while. Then add the remining the garlic. Stir and simmer together for a while. Put the butter on a separate frying pan and fry the tenderloins on both sides until golden brown. Add the fried tenderloin to the leek with garlic. Pour all the broth and cook for a few minutes. Then add the cream and season with pepper. Boil until the liquid evaporates and the sauce is formed