Preheat oven to 350 degrees. In a cup or small bowl, mix together the salt, oregano, flour, black pepper, Italian seasoning, garlic powder, onion powder, and cayenne pepper.
Place the ground beef in large bowl, and use your hands to blend in the spice mixture. If you want to smooth texture of meat that you see in a real donair shop, you must do this in a steel mixing bowl and on a sturdy surface. Pick up the meat, and throw it down with force about 20 times, kneading it after each throw. This also helps the meat hold together better when you slice it.
Form the meat into a loaf, and place it on a broiler pan. If you do not have one, a baking sheet will do.
Bake for 1 hour and 15 minutes in the preheated oven, turning the loaf about halfway through. This will ensure even cooking. This cuts better if you chill the meat overnight before slicing. For 2 pounds of meat cook longer. Start trimming at 1 hour 20 minutes and put back in oven for 30 minutes.
To make the donair sauce, mix together the evaporated milk, sugar, and garlic powder in a medium bowl. Gradually whisk in the white vinegar, adding 1 tsp at a time, until thickened to your desired consistency. Don’t need to heat.