Preheat the oven to 200 degrees top / bottom heat and finely dice the onion.
Cut the pork fillet into approx. 3 - 4 large pieces, season with salt and pepper and coat the outside with mustard. Then wrap the outside with bacon and fix it with toothpicks if necessary. Fry the meat on both sides in a pan so that the bacon and meat take on a light color. Then put the meat in a baking dish and put it in the oven for about 10 minutes.
Allow the diced onion to become translucent in the frying set. Deglaze with the white wine, stir in the ricotta and let the sauce simmer briefly. Season with soy sauce, salt and pepper.
Take the meat out of the oven, add to the sauce in the pan and let it steep for another 10 minutes.