Sprinkle one side of beef with half the flour and pound it in.

Turn the beef over and pound in the remaining flour.

Cut the beef into 6 serving pieces.

Heat vegetable oil in a 12-inch skillet over medium heat.

Cook 3 pieces of beef at a time in the oil until browned on both sides, about 15 minutes.

Drain the beef.

Add beef broth and water to the skillet.

Bring the mixture to a boil, then reduce heat to a simmer.

Cover the skillet and simmer for 15 minutes.

Add carrots, parsnips, and onions to the skillet.

Sprinkle with salt, pepper, and dried thyme leaves.

Cover and simmer until the beef and vegetables are tender, about 40 to 60 minutes.

Add cucumbers during the last 5 minutes of cooking.

Remove the beef and vegetables to a heated platter.

Skim any excess fat from the broth in the skillet.

Stir in sour cream.

Heat the gravy just until hot, do not boil.

Serve the gravy with the beef and vegetables.