Lightly spread mustard on each slice of steak; sprinkle with salt and pepper. Place 1 bacon strip and a few onion wedges on each slice; roll up; secure with toothpicks. , In a large skillet, brown beef in oil until no longer pink; drain. Add broth; bring to a boil. Reduce heat; cover and simmer for 1-1/2 hours or until meat is tender. , Remove meat and keep warm. Combine flour and water until smooth; gradually stir into broth. Bring to a boil, stirring constantly until thickened and bubbly. Remove toothpicks. Return beef to gravy; heat through. Sprinkle with parsley if desired.