Recipe courtesy Melanie Howsam, Lemon Meringue, Toronto.
Add sugar and butter to the bowl of the stand mixer. Fit a stand mixer with the paddle attachment. Cream the sugar and butter at medium speed until the sugar is no longer visible. Add the egg yolk and beat until well blended. Add ¾ cups of the flour and beat until dough becomes crumbly. Add the remaining ¾ cup flour and cream. Combine until dough comes together. Wrap dough in plastic wrap. Refrigerate for a minimum of 30 minutes.
Roll dough into 13-inch circle. Transfer to an 11-inch tart pan with removable bottom. Freeze for minimum 1 hour.
Preheat oven to 400 degrees F.
Line the tart shell with parchment paper. Fill with pie weights or baking beans. Bake pastry until light golden brown, about 20 to 25 minutes. Allow tart shell to fully cool before filling.
Whisk eggs, egg yolks, sugar and lemon juice in metal bowl until smooth. Add butter. Place the bowl with the filling over gently simmering water. Whisk until the filling has thickened, about 8 to10 minutes. Strain the filling into bowl. Stir in lemon zest. Let cool to room temperature. Once the filling has cooled, pour into the tart shell. Refrigerate. While the filling is chilling, make the meringue.
Add egg whites to a clean, grease free bowl of a stand mixer. Fit a stand mixer with the whisk attachment. Beat the egg whites on medium speed. When the egg whites have doubled in volume, increase speed to high and slowly add the sugar. Continue to beat until glossy peaks form.
Fill a piping with the meringue. Pipe meringue over top of tart. With a blow torch carefully brown meringue. Refrigerate until ready to serve.