Season the pork fillet with salt and pepper and fry on both sides. Take out of the pan and keep warm. Fry the peppers and onions in the roasting pan until the onion bubbles. Take out of the pan and keep warm.
Dust the roast with a little paprika, deglaze with the stock. Mix the sour cream and creme fraiche with the flour, stir in. Season with salt, pepper, garlic, mustard, soy sauce and possibly a splash of Worcestershire sauce and simmer briefly.
Put the meat and onions back into the sauce, add the pink peppercorns, and let them boil briefly. Season again to taste and serve sprinkled with chopped parsley.