Cut the pork tenderloin into 3 cm thick slices. If necessary, remove the firm, lateral skin and flatten each pane a little. Peel and finely dice the shallot and garlic cloves. If necessary, clean the mushrooms and cut them into slices. If necessary, rinse the sage leaves under a gentle stream of water and shake them gently until dry, then cut them into small pieces.
Meanwhile, prepare a roux sauce in a small saucepan. Mix the flour with a tablespoon of olive oil, add the milk and stir everything with a whisk until smooth. Heat, stirring frequently, until a creamy consistency is achieved, then add the cream cheese, sour cream and a little salt.
Pour this sauce, which has now assumed an almost pudding-like consistency, into the pan and mix it with the liquid there. Add the remaining sage leaves and season with salt and pepper. It goes well with pasta or baguette and green beans or tasty tomatoes.