If you baked the chicken as directed, it will naturally brown up very nicely in the oven, thanks to the Parmesan cheese which will naturally help that process. If for some reason you want it even more golden, you can broil it for a couple of minutes. The risk here is that you burn it and it's ruined. If you're not familiar with broiling food, you may want to just forget about this step. If you do want to broil it, turn your broiler to high and just keep the baking pan where it is in the middle of the oven, you don't need to move it up higher, the broiler heat is intense enough that it'll reach the chicken. Watch it like a hawk - a couple minutes is all it will take!