In a glass-measuring cup, combine the yeast and sugar. Add the water and stir well. Let rest until foamy, about 5 minutes. Sift together the flour and salt into a large bowl. Make a well in the center of the flour and pour the yeast mixture and oil into the center. Mix together with your fingers until a smooth dough forms, working in a small amount of additional flour as needed. Knead for 3 minutes.
Oil a small bowl with the remaining butter or oil. Place the dough into the bowl, turning to coat, and let rest until doubled in size, about 1 hour.
Preheat the oven to 400 degrees F.
Divide the dough into 6 pieces and gently roll into 6 circles on a lightly floured surface. Bake on a baking stone, or a lightly greased baking sheet, until just golden brown and puffed, about 12 minutes.