Coat the beef in ½ the flour, ½ the paprika and season with salt and pepper.
Spray a large frying pan with 1kal and fry the steak on a medium/high heat until it browns (I fried for around 6 minutes). Remove from the pan and pop to one side on a plate.
Spray the pan again with 1 kal, add the onions to the pan and fry for a few minutes and then add the rest of the flour. Fry for another few minutes until the onions start to soften (add a little water if the pan gets too dry)
Add the garlic and mushrooms and fry for another few minutes. Add the rest of the paprika, Dijon mustard and tomato puree, stir and fry for another minute and then add the beef stock.
Add the meat back to the pan and then stir and simmer on a medium to high heat for around 10 minutes so that the sauce starts to reduce and thicken.
Whilst the stroganoff is simmering, put the pasta (or rice) on til al dente, then drain.
Turn the heat on the sauce to low then add the sour cream and nutmeg, stir and simmer for another few minutes. Add the parsley and red wine vinegar, stir, taste and season if needed.
Stir through the pasta, coating well and serve in some nice big pasta bowls.