Mix flour and salt. Combine milk and eggs, add to flour and mix well until smooth. Pour hot drippings into shallow pan to depth of 1-inch. Pour in mixture quickly and bake in hot oven at 400 degrees for 1/2 hour. The pudding may then be placed under the rack holding the roast beef and left for 15 minutes to catch the juices from the roast. If a rack is not used, cut pudding into squares and arrange in pan around roast. Serve with the meat.