Preheat the oven to 350. Butter or spray a 9x13 pan. (Tip: I use the butter wrapper from the sauce to butter the pan!)
Mix sauce ingredients well. Some of the ingredients tend to settle, so mix well and don't be afraid to mix again later!
Slice rolls in half. (I always, always mess this up. Do not worry--it's bread and melted butter. You're fine!) Place bottom half of rolls in the prepared pan.
Spoon or brush half of the sauce onto the bottom half of the rolls. Top with ham and then cheese. You do as little or much as you like here! I usually do a double layer of ham and a single layer of cheese.
Place top half of rolls on...top. ;) Brush/spoon remaining sauce mixture on top. Try and evenly spread the onion flakes and everything seasoning!
Bake for 18-20 minutes, until cheese is melted and top of the rolls are crispy.
Let cool for about 5 minutes, cut, and serve!