Place pizza stone or inverted baking sheet in oven and heat to 500 degrees.
Heat 1 tablespoon oil in a large skillet over medium heat. Cook garlic until just tender, about 1 minute. Add chard stems and cook, stirring, until tender, about 5 minutes. Working in batches, add leaves and cook until just wilted, about 5 minutes. Season with salt and set aside.
Stretch dough into a 10-by-14-inch rectangle and transfer to a piece of parchment. Brush with remaining oil and season with salt. Sprinkle with half the Gruyere, then top with chard and sprinkle with remaining Gruyere.
Transfer to the oven: Slide parchment onto stone or baking sheet and bake pizza until cheese is bubbly and crust is golden, 13 to 15 minutes. Sprinkle with pepper flakes.
The Heat Is On
Ceramic pizza stones pull moisture from the exterior of the dough for a perfectly crisp crust. A preheated baking sheet works almost as well.
Using good dough is essential to this delicious & simple pizza recipe. I used a garlic dough from a local boutique pizzeria who sells it at my grocery store. I used red pepper flakes earlier in the process, when sautéing the garlic & swiss chard to help release some of the heat. As a finish, a light drizzle of white truffle oil took it to the next level of garlicky, earthly flavors!