Preheat a grill to moderate (if you have one with a thermostat, use 325 degrees) or heat oven to 450 degrees.
Sift dry ingredients together into a bowl.
Add shortening and cut in finely.
Add currants and toss lightly with a fork.
Add buttermilk and stir lightly with fork just until blended.
Turn out on floured board and knead lightly 4 or 5 times to smooth up.
Shape into a ball and roll into a round 1/2 inch thick.
Prick all over with fork.
Cut into 8 wedges.
Put on floured grill and bake 10 minutes on one side, turn and bake about 15 minutes on the second side or until browned and baked through.
Or put on ungreased cookie sheet and bake in oven about 12 minutes or until well browned.
Serve hot with butter.