To make the pastry, in large bowl, whisk together flour, sugar and salt. Add the butter and toss to coat. Using a pastry-blender or fingertips, work butter into flour mixture until it resembles coarse meal. Sprinkle on 1/4 cup (60 mL) ice water, tossing with a fork. Squeeze the mixture between fingers to check that it holds together. If not, toss with another 1 tbsp (15 mL) ice water. Shape dough into a disk. Cover in plastic wrap and chill at least 30 min.
On lightly floured work surface, roll pastry to fit bottom and sides of 9 in. (23 cm) pie plate. Transfer pastry into plate, lining sides. Trim off excess. Flute edge with fork or crimp with fingers. Using fork, prick bottom of pie shell every 2 in. (5 cm). Chill 15 min.
Meanwhile, preheat oven to 200ºC (400ºF). Line pie shell with foil. Fill with pie weights. Bake 15 min. to "blind bake". Remove foil and weights. Return shell to oven to bake another 10 min., or until it is lightly golden and crisp. Cool completely.
Meanwhile, make filling by whisking together sugar, cornstarch and salt in medium saucepan. Whisk in almond beverage, lemon zest, and lemon juice until smooth. Whisking continuously, bring to a boil over medium heat, then immediately reduce heat to low. Cook, stirring, 3 to 5 min. until mixture thickly coats the back of a spoon. Remove from heat. Stir in butter until melted. Pass filling through fine-meshed sieve to remove any lumps. Pour filling into cooled pie shell. Cool to room temperature.
To make meringue, in large bowl, use an electric hand-mixer to beat the chickpea liquid (aquafaba) and cream of tartar on high speed until pale and foamy. Gradually beat in sugar until soft peaks form. Note: Beating aquafaba can take longer to whip than egg whites.
To check sugar has dissolved, rub a small amount of meringue between fingertips to check there’s no grit. Beat in vanilla. Spoon meringue over filling, spreading to edges.
Meanwhile, preheat broiler. Place pie on baking sheet and broil 1 to 3 min. or until meringue is flecked with brown. Cool pie to room temperature or chill 1 hr. before serving. Best if served on same day as baked.
Use the chickpeas to make dips. Or add whole to salads, soups and stews.