How to Prepare Top Round Beef for Sandwiches
Place 20 to 24 pounds of top round beef in a shallow roasting pan. Season with salt, pepper, and garlic powder. Do not put any water in the pan. Bake at 475 degrees for 25 minutes. Lower temperature to 325 degrees and bake for 3 to 3 1/2 hours. Test with a meat thermometer. If reading shows meat is rare after time cooked, remove from the oven as the meat is still cooking. Remove meat from hot pan (save pan and juices for making au jus) and place meat in another pan to cool. When meat is cool, place in refrigerator over night or until thoroughly cooled before slicing.
Deglaze the roasting pan by placing pan with juices on stovetop on low to medium heat and scraping the browned bits from the bottom and sides of the pan while adding approximately three cups of water. Add 1 teaspoon of beef base (Knorr or any other type if fine) to 1 cup of water and pour in pan and continue deglazing. Add additional water, if needed.
Slice cold beef thinly and place on a large platter and cover with wrap until ready to heat for serving. At serving time, heat au jus so it is very hot and then turn off the heat, or leave on very low (do not boil). Add sliced beef only as long as it takes to get hot. Remove slices of beef and place immediately on rolls. DO NOT BOIL THE AU JUS WHEN THE MEAT IS IN IT OR THE MEAT WILL BE TOUGH.