1In a saucepan, bring to a boil 0.5 cup of balsamic vinegar and 4 tablespoons of light brown sugar. Reduce heat and simmer until thickened.
2Unfold the puff pastry and cut into a 1 inch border.
3Preheat the puff pastry for 5-8 minutes.
4In a bowl, mix together 0.5 block of boursin cheese, 0.5 cup of mayonnaise, 12 chopped basil sprigs, 0.5 teaspoon each of salt and pepper, 0.5 cup of freshly grated parmesan cheese, and 0.5 cup of sharp cheddar cheese.
5Spread the cheese mixture onto the pre-baked puff pastry.
6Arrange sliced tomatoes (previously salted and drained) onto the cheese mixture.
7Top with thinly sliced red onions.
8Bake the tomato pie for 18 minutes.
9Garnish with fresh parmesan cheese and basil.
10Drizzle the balsamic glaze over the finished tomato pie.