A combination of lard and yogurt gave this dough a supple texture. Though it was not as flavorful, vegetable shortening worked as a substitute for lard. If the dough doesn’t ball up in the processor, gather it together and briefly knead it by hand. Roll out the rounds as evenly as possible. Let the dough rest if it resists rolling or snaps back. And if the char on the first piadina is too light, heat the pan several minutes longer.