Sift flour, cardamom and sugar into large bowl. Rub in butter with fingers or cut in with pastry blender until size of small peas. Using fork, stir in oil. Slowly add cold water, 1 teaspoon at a time, tossing with fork until flour is moistened without being wet. Gather dough with moist hands, shape into flattened round and let rest about 15 minutes. Roll 1/8-inch thick on lightly floures board. (To facilitate rolling, dough may also be rolled between sheets of wax paper Or unrolled dough may be placed in pan and gently pressed to cover inside of pan.)
Gently lift and press onto 9-inch square tart pan with removable bottom. Cut off dough edges. Bake at 425 degrees F. 10 to 15 minutes or until golden brown. Makes 12 servings.
NOTE: Unsalted butter will give a more delicate fresh flavor in this pastry. Add a dash of salt if using.