Step 1: In a large mixing bowl, combine the active potato flake sourdough starter, sugar, vegetable oil, salt, and warm water. Stir until the sugar is mostly dissolved.
Step 2: Gradually add the bread flour one cup at a time, mixing with a wooden spoon or a stand mixer dough hook until a soft dough forms and pulls away from the sides of the bowl.
Step 3: Knead the dough for about 5-8 minutes until it is smooth and elastic. Place in a large greased bowl, cover with a clean cloth, and let rise in a warm place for 8 to 12 hours (or until doubled).
Step 4: Punch down the risen dough and turn it out onto a lightly floured surface. Divide the dough into 15 equal-sized pieces and roll each into a smooth ball.
Step 5: Place the dough balls into a greased 9x13 inch baking pan. Cover and let rise again in a warm spot for 4 to 6 hours until they have doubled in size and look very puffy.
Step 6: Preheat your oven to 350°F (175°C). Bake the rolls for 20-25 minutes, or until the tops are a light golden brown.
Step 7: Remove from the oven and immediately brush the tops with melted butter. Allow to cool slightly before serving.