Preheat the oven 400 degrees. In an electric mixer, whisk the yeast, water, and oil, together, to form a paste. Using a dough hook, add the flour and salt to the paste, mix the dough until the dough comes away from the sides and crawls up the sides of the hook. Remove the dough from the bowl and turn the dough into a greased bowl, cover. Let the dough rise until double in size, about 1 hour.
Turn the dough out onto a floured surface and divide into four 4-ounce balls, cover. Let the dough rest for 10 to 15 minutes. Press each dough out into a 10-inch circle about 1/2- to 1-inch thick. Lightly brush the dough with olive oil.
Divide the potatoes into four portions and season with salt and pepper. Cover each dough with the potatoes, leaving a 1-inch border. In a small mixing bowl, toss the red onions with the extra-virgin olive oil. Season with salt and pepper. Place a layer of the red onions on top of the potatoes.
Sprinkle each pizza with the grated cheese. Drizzle each pizza with the truffle oil.
Bake for 15 to 20 minutes or until the crust is crispy and golden-brown. Garnish the pizza with chives.