Warm the olive oil in a skillet and add the sliced onions and ½ teaspoon salt. Cook, stirring, until softened, about 8-10 minutes, then put the lid on and turn the heat to low. Continue to cook about a half hour longer, stirring occasionally, and adding a little water if the onions start to stick. Take the lid off, then turn the heat up to get a nice brown caramelized onion mixture. If the bottom turns brown, this is a good thing. Take the pan off the heat, put the lid on and let it steam a few minutes, then uncover and stir the brown bottom back into the onions. Taste for salt and add more if needed, and a few grinds of black pepper. Set aside.
Sprinkle the bacon with a little brown sugar and either pan fry or place in a hot oven on a sheet pan until cooked through and crispy (if using pancetta or prosciutto, you will need a little oil in the pan so it doesn’t stick). When cooked and crispy, chop into pieces and set aside.
Preheat the oven to its hottest setting, usually around 500 degrees, and if you have one place your pizza stone in the bottom of the oven.
Dust a pizza peel with cornmeal or semolina, or flour if you don’t have those. You can also just use your wood board, dusted liberally with flour, so that the dough will slide off easily onto the pizza stone in the oven. If you do not have a stone, oil a baking sheet. Stretch your dough from the center out, using your hands to coax it into a rough circle shape and place on your peel or baking sheet.
Layer the onions on the bottom of the dough, then scatter the blue cheese over top. Finally top with the bacon, and place in the oven. Cook 8-10 minutes until browned. Serve immediately.