Preheat oven, set with a pizza stone or baking steel, to 550 degrees.
Cook the mushrooms in butter, salt, and balsamic vinegar until browned and caramelized.
Prepare the pizza dough and assemble by topping it with mushrooms, ricotta, garlic, and chili flakes.
Bake the pizza until bubbly and golden brown, then drizzle with white truffle oil and garnish with chopped green onions before serving.