Loaded Potato Quiche

350 degree oven Spray 9 1/2" glass deep pie plate with cooking spray. Place Bisquick mix in medium bowl. Cut in butter, using pastry blender (or pulling 2 table knives through mix in opposite directions), until crumbly. Add boiling water, stir vigorously until soft dough forms. Using fingers dipped in Bisquick mix, press dough on bottom and up side of pie plate, forming edge on rim of plate. Sprinkle ham, potatoes and cheese and three tablespoons of onions in crust. In medium bowl, beat eggs and half and pepper until blended. Pour over ingredients in crust. Bake 1 hour 5 min or until knife inserted in center comes out clean. Let stand 15 min before serving. Top with bacon, sour cream and onions if desired.