1Heat oven to 400°F. In medium saucepan, cook potato slices in boiling salted water over medium-high heat for 5 minutes. Drain.
2Fry bacon in large skillet over medium-low heat until crisp. Drain on paper towels. Crumble bacon; set aside. In same skillet with bacon drippings, cook onion 5 to 7 minutes or until softened and separated into rings, stirring frequently.
3Separate dough into 10 biscuits. Separate each biscuit into 2 layers; place biscuit rounds on ungreased large cookie sheet. Flatten each slightly. Spread each lightly with mustard. Top each dough round with potato slice and onion.
4Bake at 400°F. for 9 to 15 minutes or until crusts are crisp and golden brown. Top each mini pizza with sour cream and crumbled bacon. Sprinkle with parsley.