Method
Pre-fire your wood oven. It should be around 350°C when you come to cook.
Place a large, heavy-based pan over a medium heat. Add the butter and 1 tbsp extra virgin olive oil. When it’s bubbling away, add the onions, along with a good pinch of salt and some black pepper. Cook, stirring regularly, for 15–20 minutes or until the onions are soft and just beginning to caramelise at their edges. Stir in the garlic and thyme and cook for 3–4 minutes longer. Set to one side.
Sprinkle your work surface with a little polenta or semolina. Place one ball of dough on the surface and stretch out by hand to a round, 25–30cm in diameter. Repeat with the second piece of dough.
Dust a pizza peel with polenta or semolina (if you don’t have a peel, an upturned baking tray is a good substitute). Transfer one pizza base to it. Arrange half the onions over the pizza base and then sprinkle over a quarter of the Parmesan. Lay half the mushrooms over the cheese, trickle with 1 tbsp extra virgin olive oil and season with salt and pepper. Scatter over another quarter of the Parmesan, followed by a small handful of finely chopped chives.
Slide the pizza into the wood oven and cook for 3–5 minutes or until crisp, golden and bubbling. Remove the pizza to a plate or board, and trickle over the truffle oil. Assemble and bake the second pizza.
