1. Prepare the pizza dough. In the bowl of a stand mixer fitted with the dough hook attachment, stir together the warm water with the yeast. Allow the mixture to sit for about 10 minutes, or until the yeast starts to foam up (proofing the yeast). If this doesn’t happen, your yeast may be dead. Start again with new yeast and water.
2. Add 1 cup of the flour, the honey, salt and olive oil. Mix together on low for 1 minute, before adding the last cup of flour. Once the dough starts to form together, increase the speed to medium-high and run the mixer for about 5-6 minutes; if the dough continues to stick to the sides of the bowl, add an additional tablespoon of flour at a time, until the dough pulls away from the sides of the bowl (you may need to use up to 1/4 cup more flour in total). After 5-6 minutes, remove the dough from the bowl, and shape it into a round ball. Place the dough into a large bowl that has been sprayed with non-stick spray or lightly greased with olive oil. Turn the ball of dough around in the bowl to lightly coat all surfaces. Cover the bowl tightly with plastic wrap or a damp towel and leave it to rise at room temperature (away from cold drafts) for about 1 1/2 hours, or until the dough has doubled in size.
3. While the dough is rising, caramelize your onion. Melt the butter in a large skillet (cast iron or stainless steel is best) over medium heat. Add the sliced onion, and stir to coat. Cook the onion for 40-55 minutes, stirring them every 8-10 minutes with a wooden spoon, ensuring that all bits (fond) that collects on the bottom of the pan is scraped up and stirred. Taste a golden onion around 40 minutes, and if it tastes good to you, add the wine/vinegar/water to deglaze the pan. Stir/scrape up all of the remaining fond that has collected on the bottom of the pan. Turn off the heat and allow the onions to cool.
4. Preheat the oven to 450 F.  When your pizza dough is ready, punch it down lightly to release some of the air. Place it on a floured surface and roll the dough into a 12″ circle. Pour the oil into the bottom of a 12″ cast iron skillet* and swirl it around to coat. It will seem like a lot of oil, but trust me – it really helps to deliver that deep-dish flavour to your crust. Sprinkle some cornmeal over top of the oil (if desired). Place the circle of dough into the skillet, and fold up the sides slightly to create a bit of a crust around the edge.
5. Top your pizza starting with tomato paste, chili flakes, and mozzarella cheese. Add the sausage, pepper and feta, and finish it off with the caramelized onion.
6. Bake the pizza for 15-20 minutes, or until the edge of the pizza has turned a golden brown. Remove the skillet from the oven, and run a knife around the edge of the pizza. Using a spatula, lift the pizza out of the skillet and onto a large wood cutting board to slice and serve. Enjoy immediately!

Leftover pizza can be stored in the fridge, in an airtight container, for 3-4 days.