Preheat oven to 475 degrees. Form dough (as directed in Basic Pizza Dough recipe) in a 9-by-13-inch rimmed baking sheet. Sprinkle cheese evenly over dough. Arrange scallions in an abstract pattern, as shown on page 88, pressing into dough, then press mushrooms into dough between shapes. Drizzle with oil and sprinkle with salt.
Bake until cooked through and crust is golden on edges and bottom, about 17 minutes.
Using a metal spatula, slide pie onto a cutting board. Slice into 6 pieces and serve.