Definitely part skim cheese. I don't know what kind of cheese options you have in Pakistan, but the lower the fat, the greater propensity for spotting. Some brands of cheese spot more readily than others, but finding them will involve trial and error.
You could also recreate this effect by cheating a little bit. Sprinkle most of the cheese on the pizza, lightly mist the cheese with a water sprayer, then apply the rest of the cheese sparsely. The dry cheese will brown at a faster rate than the wet cheese.