-(4 ounces) Preheat oven to 400. Grease bottom of a 23 cm square baking pan. Brown ground beef in skillet; drain and reserve drippings. Saut onion in reserved beef drippings until tender; drain. Beat egg in mixing bowl; stir in sour cream, salt, and pepper. Prepare biscuits as directed; except--after kneading gently, divide dough in half. Roll out first half on lightly floured board or pastry cloth to fit dimensions of pan. Pat dough tightly into bottom of pan. Sprinkle dough evenly with ground beef. Add onion layer and pour sour cream mixture over all. Sprinkle with cheese. Repeat rolling procedure with remaining biscuit dough. Place dough on top of casserole mixture. Bake for 30 to 35 minutes or until golden brown. Cool for 10 minutes before serving. Cut into squares to serve.