1. n a small saucepan, cover potato with a half-inch of water and bring to a boil. Simmer until just tender when pierced with a fork, about 12 to 14 minutes. Let cool until comfortable to handle. Slice into quarter-inch thin slices and set aside.
2. While potato is cooking, preheat oven to 450 degrees Fahrenheit. Sprinkle a rimless baking sheet with one tablespoon flour and set aside.
3. On a lightly floured surface, roll out pizza dough to a 10-inch circle and transfer to prepared baking sheet. Prick dough all over with a fork to help prevent large bubbles from forming during baking. Sprinkle with sliced garlic, extra-virgin olive oil, and salt. Layer potato slices all over pizza and top with cheese and scallion.
4. Bake at 450 degrees Fahrenheit for 12 to 16 minutes or until crust is golden brown and cheese is bubbly. Top with avocado slices once out of the oven. Slice into six to eight wedges and serve immediately.