If you cannot find the small blue or prune plums, then use apples. I have been disappointed in the prune plums this year, which are large and very sour. The small ones have been much better. If using apples, use 3 lbs (1.5 kg) mixed varieties. Olive oil pastry means you can serve this after a meat dish and it is healthier than vegetable shortening (unless you can find the organic kind). Good olive oil pastry is flaky and tasty but remember not to use a strongly flavoured oil.
- 3 cups all-purpose flour
- 2 tbsp sugar
- 2 tsp kosher salt
- 3/4 cup olive oil
- 1/3 to 1/2 cup cold soda water
- 2 tbsp cider vinegar
- 1 cup granulated sugar
- 1/4 cup tapioca flour or 3 tbsp cornstarch
- 2 tsp cinnamon
- 1 tsp ground ginger
- 3 lbs (1.5 kg) blue plums, pitted, quartered
Stir flour, sugar and salt in a large bowl. Whisk oil with 1/3 cup soda water and vinegar. Pour liquid mixture into flour mixture, stirring with a fork. When liquid has been absorbed, use hands to gently knead into a ball. If it feels too dry add the extra water. Wrap 1/3 dough with plastic wrap and set aside.
Roll out remaining dough on a well-floured board into a 1/8-inch thick circle. Keep flouring the surface and the rolling pin to prevent the dough from sticking. The pastry should be large enough to fit a 9-inch tart pan with a removable bottom. Fit pastry into pan, pressing into the sides. Leave overhanging pastry attached to help seal pie later. Use extra pieces of pastry to patch if needed. Chill for 30 minutes.
Preheat oven to 450 F.
Combine sugar, tapioca flour, cinnamon, ginger and plums in large bowl. Toss together. Place in chilled tart shell, mounding them in the middle. Roll out remaining pastry to cover plums. Pinch edges of dough together and trim off excess. Cut a few slits in the top of the pie.
Place pie on a baking sheet and bake in the lower third of oven for 15 minutes. Reduce heat to 375 F. Bake for 30 to 40 minutes longer or until juices are bubbling and pastry is golden. If pastry gets too brown, cover with a sheet of parchment paper.