Although these directions are for roast turkey, you can use beef broth and the drippings from roast beef to make beef gravy.
Recipe from Better Homes and Gardens
Pan drippings from roast turkey
1/4 cup all-purpose flour
Chicken broth or water
Add all at once to flour mixture. Cook and stir over medium heat until thickened and bubbly. Cook and stir 1 minute more. Season with salt and pepper. Makes 2 cups (8 to 10 servings). Recipe may be doubled.