Mix Flour And Salt in a small bowl. Add milk gradually, whisking until smooth. Add water and eggs and whisk until foamy. Cover loosely and let stand for 30 minutes. Preheat oven to 500F. Pour 1/2 teaspoon drippings into each of six muffin tins, and heat in the oven 1-2 minutes. Beat batter until foamy again and spoon 3 tablespoons batter into each cup. Bake 8 minutes without opening the oven door. Serve immediately with roast beef and gravy.
