Place a large saucepan over medium heat and add the butter, onion, thyme and salt.Saute for 5 minutes, until the onion is beginning to turn translucent.Add the diced pork and cook for 5 minutes, until the pork has started to color.Add the seeded mustard, chicken stock and sour cream and bring to a simmer.Simmer for 20 minutes before adding the mushrooms.

Stir well.Continue to simmer for 40-60 minutes, until the pork is tender and the sauce has thickened.Remove from the heat, add the fresh basil and stir through.Serve and enjoy.