Fresh Basil and Strawberry Meringues

Position an oven rack in lower third of oven. Preheat to 300F. Line a baking sheet with parchment paper. Stir 3/4 cup sugar with cream of tartar and salt in a medium bowl. Set aside. Beat egg whites in a large bowl, using an electric mixer on high, until soft peaks form when beaters are lifted, 1 to 2 min. Gradually beat in sugar mixture, a spoonful at a time, until stiff, glossy peaks form, about 6 more min. Add vinegar and vanilla and beat for 1 min. Spoon meringue onto parchment in 6 large dollops, dividing evenly. With the back of a spoon, gently spread the meringue into 5-in. circles. Reduce heat to 200F. Bake pavlovas in lower third of oven until tops are crisp and dry, 2 hours to 2 hours and 15 min. Turn off oven and let them dry in oven for 30 more min. Remove from oven and leave on parchment until completely cool. Stir strawberries with 1/4 cup sugar in a medium bowl. Let stand at room temperature, stirring occasionally, until meringues are ready. Whip cream in a medium bowl with an electric mixer until stiff peaks form when beaters are lifted, about 2 min. To assemble, top each meringue with 1/2 cup whipped cream, then 1/2 cup of strawberries. Drizzle with juice. Garnish with basil leaves.