Preheat oven to 500℉.
Take half the pizza dough and work dough on floured surface. Shape dough into a round shape. With four fingers together press the dough down firmly 5 rows. Press and turn the pizza dough in clockwise motion.
Transfer dough onto a greased lipped baking tray. Gently pull dough into rectangular shape. Should the dough retract back to center, let the dough rest 5-10 minutes before retrying. This helps to relax and stretch the proteins in the dough. Spread dough as evenly as possible. Let rest another 5 minutes.
While dough is resting in between stretching and shaping, work on your sliced mushrooms. In a pan, sauté mushrooms in a little olive oil. Season with a little salt and pepper. Let the mushrooms loose water content and become smaller. Set aside to cool.
If dough retracted, repeat to shape dough. Depending on the size of your lipped baking tray, there might not be enough dough to be flush with the edges. That's ok! Proceed on.
Spread the preserves onto the dough, leaving a 1" border. Sprinkle evenly onto dough the Gruyère cheese, dried thyme, and cooled mushrooms. Add sliced fresh mozzarella and evenly distribute red onion.
Cook pizza for 18 minutes, turning pizza halfway through baking.
Remove from oven and let rest for 3 minutes and transfer to cutting board.
Add handful of arugula evenly across pizza. Tear Jambon Sec and spread evenly. Sprinkle shaved truffle over arugula and drizzle lightly with truffle oil.
Slice into 8 squares using pizza roll cutter.