Fill a cup with ice and water. Sift the flour and salt into a bowl. Cut in the shortening to make pea-size pieces. Add the tablespoons of ice water from the cup until dough holds together. Form the dough into a ball. The dough is now complete. Put it into a plastic bag or wrap it up and refrigerate for at least 15 minutes.
Roll the dough between two sheets of waxed paper. Cut the shells using a large glass or your smallest pot. You should have about 12 shells when finished. Put these shells into a greased muffin or tart pan.
Preheat oven to 350 degrees F (175 degrees C)
Put walnuts and coconut on baking pan and roast for 5-10 minutes, until brown. Remove from oven and set temperature to 450 degrees F (230 degrees C).
Fill the bottom of each tart shell with about 10 raisins each.
Whisk together sugar, egg, butter, vanilla and hot water. Add coconut and walnuts. Pour mixture into tart shells, filling 2/3 full and no more.
Bake in 450 degrees F (230 degrees C) oven for 10-12 minutes or until golden brown. Let cool before attempting to remove. Makes 12 tarts.