Wash the boneless pork and pat dry. Cut the meat into thick strips.

Peel the onions and slice into rings.

Heat the canola oil in a large skillet over medium heat and add the pork pieces.

Stir the pork until it becomes golden brown on all sides.

Season with salt and freshly ground pepper to taste.

Remove the browned pork from the pan, leaving the juices behind.

Wrap the pork in aluminum foil and store in a warm place.

Add the onion rings to the pan, sprinkle with the sweet paprika and cook until the pieces become golden brown, stirring often.

Deglaze the pan: Add the brandy and the beef stock to the pan. Bring the mixture to a 
boil scraping the browned pieces off of the bottom of the pan.

Let the mixture boil for no more than 2 minutes.

Whisk together mustard and sour cream. Stir it into the pan. Simmer for 3 min.

Add the browned pork pieces back to the pan.

Season with salt and freshly ground pepper.

Simmer for 8-10 min more.

Transfer the content of the pan to a serving platter.

Garnish with chopped fresh parsley and serve.