Line baking sheet with parchment paper; draw 12- x 7-inch (30 x 18 cm) rectangle. Turn paper over.
In large bowl, using electric mixer on medium speed, beat egg whites until soft peaks form. Reserve 1 tbsp (15 mL) of the sugar in medium bowl. With mixer running, gradually beat in remaining sugar, 2 tbsp (25 mL) at a time. Add cornstarch and 1 tsp (5 mL) of the lemon juice. Beat on high speed, until stiff, glossy peaks form.
Spread meringue into rectangle on baking sheet; dollop jam on top, swirl with tip of knife.
Bake in 250 F (120 C) oven until crisp on outside; and a little sticky inside, about 1 hour and 15 minutes. Turn oven off, open door a crack; let meringue cool completely for about 2 hours. Transfer to serving platter.
To the reserved sugar, add strawberries, remaining lemon juice and rind; stir together. In large bowl, using electric mixer on high speed, whip cream, yogurt, icing sugar and vanilla until soft peaks form and mixture is thick. Spread over meringue; spoon strawberries with juice over top.