Heat oven to 450°F. In medium bowl, using pastry blender, cut shortening into flour until mixture looks like coarse crumbs. Sprinkle flour mixture with vinegar; add water, 1 tablespoon at a time, while tossing and mixing lightly with fork. Add water until dough is just moist enough to hold together.
Shape dough into ball. With floured fingers, press dough evenly over bottom and up side of 10-inch tart pan with removable bottom or 9-inch glass pie plate. Flute edge, if desired. Prick bottom and sides of pastry generously with fork. Bake 8 to 12 minutes or until lightly browned. In 1-quart saucepan, melt chocolate chips and half-and-half, stirring until smooth. Spread in shell. Cool slightly; refrigerate until chocolate is firm, about 15 minutes.
Meanwhile, in 1-quart saucepan, heat topping ingredients to boiling, stirring until sugar is dissolved. Boil gently 3 to 4 minutes or until most of cranberries pop. Cool at least 30 minutes.
In small bowl, beat milk and pudding with electric mixer on low speed about 1 minute or until blended; stir in sour cream and orange peel. Let stand 5 minutes. Pour over chocolate layer in shell, spreading to cover evenly. Spoon cooled cranberries over filling, covering completely. Refrigerate at least 1 hour until serving time. Let stand at room temperature 10 minutes before serving. Cover and refrigerate any remaining tart.