Chicago Deep-Dish Pizza (Cheese Under the Sauce)

Variations

• Stuffed pizza: once filled, a second thin sheet of dough goes over the top and the sauce is spread on that. Deeper than deep-dish, with more cheese. ko.wikipedia says Chicago chains built it in the 1970s on an Easter pie from Basilicata.
• Tavern style: the same city's thin, crisp pizza, rolled out with a pin and cut into squares rather than wedges. Its layers go in the ordinary order, and its bake is short.
• A sheet of sausage: raw sausage pressed over the cheese in one layer, as above, is the common Chicago order. The fat that runs out of it soaks down into the cheese.
• Spinach deep-dish: spinach squeezed hard and laid over the cheese. Unsqueezed, its water runs down under the cheese.

Tips

• A pizza that solves it with the order, not by going light. Margherita pizza calls going light on sauce and cheese "a question about the clock, not about taste." and gives the reason: "the time available is seven to ten minutes" This pizza bakes a thick dough in a deep pan for over half an hour. So it loads both, and turns the stack over instead.
• Two reasons for the upside-down order. One is why the cheese sits straight on the dough. Nachos says the same thing: "melted fat is what a chip's surface can hide behind" The melted fat of the mozzarella puts a film between the sauce's water and the dough. The other is why the sauce goes on top. Cheese under the oven's top heat for thirty minutes colours too far and its fat splits out; under a layer of tomato it only melts. Chicken parmesan uses the opposite order — "the cheese goes on top of the sauce, so what is wet is a measured amount with fat above it." — for a few minutes under the grill; this is half an hour in the oven. The same two layers, and the clock decides which goes on top.
• Low-moisture mozzarella, thin, with no gaps. Mozzarella says of the fresh kind that "a wet ball weeps in the oven and soaks the base." A thin pizza gets by with thirty minutes of draining; over half an hour of baking that is not enough, so this uses a low-moisture block. Overlapping the slices is for the same reason: where there is a gap, the sauce reaches the dough.
• The sauce goes on raw and drained. The only surface exposed to the oven is the sauce on top, and raw tomato reduces there to the right thickness as it bakes. A sauce cooked down beforehand is over-reduced after thirty minutes and catches at the edges.
• The base and sides fry in the oil. Cornbread heats its pan until it smokes before the batter goes in, and so "The base and sides fry rather than bake". A deep-dish pan takes the dough cold, but with plenty of oil, and thirty minutes brings that oil up to do the same job. That is why it bakes on the lowest shelf, nearest the heat. The cornmeal adds crunch to that crust.
• Rest it ten minutes before cutting. Straight out of the oven the cheese under the sauce is close to liquid. A few minutes in the pan firm it enough not to run.