Place the flour in a large bowl (or the bowl of a stand mixer). In a separate bowl, add the water, followed by the yeast, salt and olive oil. Mix and pour over the flour. Leave to rest, covered with a kitchen towel, for 10 minutes. 

Fit the mixer with the dough hook and mix on low to medium speed for 10 minutes or until all the ingredients are fully combined and you have a smooth, silky dough with good elasticity.

Tip: If you don't have a stand mixer, mix the ingredients with a wooden spoon or your hands, then knead by hand until a smooth dough forms, about 15 minutes. 

Cover the dough and leave to rise at room temperature for 3 hours, stretching and folding it in the bowl after every hour. 

Tip: To stretch and fold, wet your hands and pinch the edge of the dough in the 1 o’clock position between your thumb, index, and middle fingertips down to your second knuckle, then pull the edge a bit (stretch) and fold over the top of the dough (past the centre) and release. Give the bowl about a ¼ turn and repeat this process every hour for a total of 3 times. 

After 3 hours, generously drizzle the bottom and sides of your baking pan with olive oil. This will help the pizza develop a nice crust and ensure your base is crunchy. Place the dough in the pan, cover it with the lid, and leave it to proof in your fridge overnight or up to 24 hours. (Be sure to remove the dough from the fridge around 3 to 4 hours before cooking to allow it to come to room temperature.)

If using a fresh onion, peel and finely chop it. Heat the oil in a large saucepan over low heat for about 1 minute; add the onion and cook for about 3 minutes or until it becomes translucent. 

Add the tomato paste and stir-fry for 1 to 2 minutes; add the remaining ingredients for the curry sauce, stir and simmer over low heat for about 15 minutes. Blend, remove from the heat and set aside.

Tip: If using onion powder, add it to the pan after the tomato paste.

Heat the vegetable oil over medium heat in a clean pan for about 1 minute. Add the bratwurst and cook them until golden brown on all sides (turning every 2 minutes to avoid burning) for about 8 minutes total. 

Remove the bratwurst from the pan and cut them into ½-inch (1-centimetre) thick slices. Add them to the curry sauce and set aside until ready to use.

Using the pads of your fingers, gently press the surface of the dough into your pan, shaping and pushing it into the corners. If the dough is not very pliable, let it rest for 30 minutes and repeat this step. Once the dough has relaxed, dimple it with your fingers again.

Fire up your oven and allow it to preheat for 15 to 20 minutes. Aim for 300 °C (570 °F) on your pizza stone. (If using Ooni’s Detroit-style Pizza Pan, do not exceed 370 °C / 700 °F.) You can check this quickly, accurately and from a safe distance with an infrared thermometer. 

Once the oven is up to temperature, pre-bake the pizza dough without any toppings for about 7 minutes; using gloves, carefully remove the pan from the oven.

Spread the sausage slices evenly over the dough, followed by a third of the sauce. Sprinkle the grated Butterkäse and Gouda over the sauce, making sure you pay particular attention to the edges – this will create the “frico” or cheesy, crusty crown. Spoon two vertical lines like racing stripes over the pizza using the remaining curry sauce.

Bake the pizza for another 10 to 12 minutes or until the cheese is golden brown. Keep an eye on the pizza, and if necessary, turn the pan halfway through cooking to achieve an even bake.

Remove from the oven, slice, serve and enjoy!