Preheat oven to 525 degrees.
Heat 2 T olive oil in a large skillet over medium heat.
Add mushrooms and cook, stirring occasionally, until beginning to brown, about 5 minutes. Remove from heat and set aside.
Roll dough on a floured surface into the desired shape.
Scatter garlic over the dough, then sprinkle with mozzarella and half of the mushrooms.
Save the other half of the mushrooms. Drizzle the remaining 1 tablespoon of olive oil over the pizza.
Place in a preheated oven on the bottom rack and cook for 10-15 minutes.
Toss arugula with olive oil, lemon, and kosher salt in a small bowl. Set aside.
Remove the pizza from the oven. Top the pizza with the arugula, reserved mushrooms, and cheese. Serve immediately.