1Combine the flour, salt, yeast, water, milk and oil in the bowl of a stand mixer. Using the dough hook, knead on medium speed for 10 minutes until the dough is smooth and elastic.
2Cover the bowl with plastic wrap and let the dough proof in a warm place for 1 hour, until doubled in size.
3Turn the dough onto a lightly floured countertop and divide into two even pieces. Shape each piece into a smooth ball.
4Place the balls 4 inches on a lightly oiled baking sheet. Drizzle a little extra oil over each one and spread to coat the dough. Cover with plastic wrap and refrigerate for 12-24 hours.
5Meanwhile, to make the pizza sauce, process the tomatoes in a food processor or blender until smooth. Heat the oil in a small saucepan over low heat. Add the garlic and cook, stirring, for 30 seconds or until fragrant. Stir in the tomatoes, oregano, salt and pepper flakes, chilli and bring to a simmer. Simmer for 45 minutes, stirring occasionally, until the sauce is thick. Cool. Reserve 5 1/2 fl oz (2/3 cup) of the sauce for this recipe. Transfer the remaining sauce to an airtight container. Store in the refrigerator for up to 1 week or freeze for up to 3 months.
6When ready to prepare the pizzas, remove the dough from the refrigerator and stand, covered, at room temperature for 1 hour.
7About 12 minutes before the dough is finished resting, select the THICK CRUST setting and preheat the oven (preheat can take up to 12 minutes).
8Working with one piece at a time, dip the base of the dough in the semolina mix, press into a 6-inch circle, then gently stretch it into a 9-inch - 11-inch circle.
NOTE: To make the semolina mix, combine equal quantities of semolina and all-purpose flour. Store in an airtight container in the pantry.
9Lightly sprinkle the pizza peel with the semolina mix. Carefully transfer the dough onto the pizza peel, gently shaking off any excess semolina mix.
10Spread the dough with half the reserved pizza sauce, leaving a ½-inch - ¾-inch border. Sprinkle with half the shredded mozzarella and half the mushrooms.
11Use the pizza peel to transfer the pizza to the oven. Cook for 9 minutes or until the base is golden and crisp and the cheese is melted.
12Slide the pizza peel under the pizza, remove it from the oven and transfer to a cutting board.
13To serve, top with half of the fresh mozzarella and oregano. Repeat with the remaining dough, reserved pizza sauce and toppings.