rectangles crosswise in an ungreased 15 x 10 x 1-inch baking pan; presss over bottom and 1 inch up the sides. Seal perforations. Bake 14 to 19 minutes or until golden brown. Cool completely. 2>. Blend sour cream, horseradish, salt and pepper until smooth. Spread evenly over crust. Top with remaining ingredients. Cut into appetizer-size pieces. Refrigerate.