Line baking sheet with parchment paper or foil. Trace an 8-inch circle on the paper and turn over. Using an electric mixer, beat egg whites with cream of tartar and salt in a medium bowl until soft peaks form. Gradually beat in first amount of sugar until stiff, glossy peaks form. Sift cocoa powder and cornstarch over mixture and gently fold in. Add vinegar, vanilla and chocolate, gently folding in. Spoon mixture onto parchment paper, building the sides up to form a shell. Bake at 275 F for 1 1/2 hours or until crispy outside and soft in center. Transfer to cooling rack and cool completely before placing on a serving dish. For topping, slice strawberries and set aside. In small bowl, whip cream with second amount of sugar and spread over meringue. Top with strawberries and drizzle with melted chocolate. SERVES 6 TO 8.