In a large bowl, add the flour, season with salt and pepper and stir well. Add the meat and thoroughly coat in the mixture.
Place a deep pan over medium to high heat. Once it gets hot, add the olive oil and the meat in batches. Brown the meat on both sides, transfer to a plate and set aside.
Using the same pan and without cleaning it, lower heat to medium. Add the garlic and vinegar. Scrape the bottom of the pan with a wooden spoon and cook for 1-2 minutes.
Add the meat back to the pan. Deglaze pan with the wine, allow the alcohol to evaporate and add the stock, mustard and half of the parsley.
Cook for 2-3 minutes, until the sauce thickens nicely. Remove pan from heat, add the remaining parsley and mix.