The day before I want this pizza for breakfast, I get out the baking sheet I use for pizza. I slice a large potato thinly and a large onion - toss them gently with a little oil or bacon grease (not too much because I want them to get dry and roasted), some salt and pepper. I spread the potato and onion over the pan and since this is going to be the pizza pan, I can see the amount of topping I am making. I like a single layer of potatoes and onions. Pop the pan of veggies into a hot oven to roast - maybe in tandem with another oven project? and mix up a half-batch of pizza dough.
When the potatoes and onions are tender and brown in spots, let it cool on the counter. Cover it. Now you are ready for the morning.
I do not refrigerate the potatoes and onions because I'm not worried about anything happening to them and I don't want to make another dish dirty (or make space in the fridge for the big pan).
In the morning, turn the oven to preheat to 500. Slide the potatoes and onions off the baking sheet, sprinkle it with cornmeal, and stretch/pat the dough onto the sheet. Shingle the potatoes and onions on the dough, slice some cheese (I used Swiss here, but I would also use an aged cheddar or fresh mozzarella) and put it on sparingly. Bake the pizza at 500 for 12-15 minutes.
Perfect served with a side of applesauce and a deep cup of black coffee.