Fry the pork strips briefly in a little oil. Dice the onion and add to the meat, fry briefly. Add the sour cream, crème fraîche and the processed cheese, stir well and simmer gently with the lid closed over medium heat for about 40 minutes. Season to taste with salt and pepper.
Add the butter vegetables about 10 minutes before the end of the cooking time, stir well and let simmer. Finally, season again with salt.