Melt butter over medium-low heat. Sprinkle in the pepper, whisk to combine.Slowly add in ¼ cup of flour, constantly whisking to combine. After a minute or two of whisking the mixture will be thick.Combine the broths in a measuring cup and slowly begin to pour into the flour mixture, whisking constantly, until smooth and well blended. Allow to cook several minutes until thickened.Toss together the hot french fries with cheese in an oven proof dish or skillet. Pour your desired amount of gravy on top and pop back in the oven for a minute or two to let the cheese melt even more. Serve immediately. Enjoy!