Heat oven to
400F (205C). Have ready a lightly greased 10-inch (25.5cm) heavy iron
skillet that can go in the oven. Sift 2 cups (500ml) flour, baking powder
and 1 tsp (5ml) salt into a bowl. Add shortening and cut in finely with a
pastry blender or two knives. Add enough of 1 cup (250ml) milk to make a
soft dough that is easy to handle, mixing lightly with a fork. Turn out on
lightly floured board and knead gently about 6 times to smooth and round
up. Roll into a circle about 14 inches (36cm) in diameter. Lift dough into
skillet and let excess hang over outside.
Combine
rhubarb, apples, 2 cups (500ml) sugar, 1/3 cup (80ml) flour, mace and 1/4
tsp salt and pile the mixture into the dough-lined skillet. Dot fruit
mixture with butter. Fold the overhanging dough in over the fruit, leaving
centre uncovered. Brush top of dough lightly with milk and sprinkle
generously with sugar. Bake about 50 minutes or until fruit is tender.
Cover loosely with aluminum foil after the first 30 minutes baking to keep
the top from browning too much. Serve warm, cut in wedges. Top with
whipped cream.