Meatloaf often has fillers, such as bread crumbs or crackers, that give the finished product bulk and keeps it from shrinking too much while cooking. These fillers also help retain the moisture in the meat. If you do not have filler material or simply prefer an all-meat version, you can make the meatloaf without them. Use ground beef with a higher fat content, because ground beef that's 90 percent lean will be quite dry without adding fillers.
Preheat the oven to 350 degrees Fahrenheit.
Wash your hands and add the beef, mushroom soup mix, onions, pepper and pepper flakes to the large bowl. Add the steak sauce and the egg.
Mix the ingredients together with your hands. You can use a spoon if you prefer, but hand mixing will blend the ingredients better.
Shape the seasoned meat into a rough loaf and transfer it to the meatloaf pan. Pack the meat tightly into the pan.
Wash your hands and mix the ketchup, Worcestershire and hot sauce together in a small bowl. Pour the ketchup mixture over the loaf and spread it across the loaf with the pastry brush.
Bake the meatloaf for approximately one hour. Transfer the loaf to a serving plate and let it rest for 10 minutes before slicing or serving.