1Heat oven to 350°F. Spray 9 1/2-inch glass deep-dish pie plate with cooking spray.
2Place 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.
3Sprinkle ham, potatoes, cheese and 3 tablespoons onions in crust. In medium bowl, beat eggs, half-and-half and pepper until blended. Pour over ingredients in crust.
4Bake 1 hour 5 minutes or until knife inserted in center comes out clean. Let stand 15 minutes before serving. Top with bacon, sour cream and additional onions.