PLACE tomatoes on parchment paper-lined full sheet pan (or half sheet pan for trial recipe). Brush with 6 Tbsp. of the dressing (or 1-1/2 Tbsp. of the dressing for trial recipe). Bake in 325ºF-convection oven 8 to 10 min. or until tomatoes are tender; cool. Set aside while preparing tarts.
MIX cheeses, egg yolks, 4 of the whole eggs (or 1 of the whole eggs for trial recipe), the onions, basil and parsley until well blended; set aside.
BEAT remaining egg. Place 1 pastry sheet on cutting board; brush with some of the egg. Cut center from second puff pastry sheet, leaving a 1-inch border on all sides. Remove center; reserve for another use. Place pastry border over the full puff pastry sheet; press pieces gently together to secure. Repeat with remaining puff pastry sheets to form four tarts (or one tart for trial recipe). Brush edges with remaining beaten egg. Fill centers of tarts with cheese mixture, using about 1 cup of the cheese filling for each tart. Arrange 6 tomato slices in rows over cheese filling in each tart.
BAKE 10 to 12 min. or until filling is set. Brush evenly with remaining 6 Tbsp. dressing (or remaining 1-1/2 Tbsp. dressing for trial recipe). Drizzle each tart with 1 tsp. of the balsamic glaze just before serving. Serve warm or at room temperature.