Preheat oven to 425°F (220°C).
Unroll pastry sheet on parchment and place on baking sheet. Fold over 1/2 inch (1 cm) of each edge of pastry andpress down firmly.
Using a fork, prick inside base of pastry. Bake for about 6 minutes or until light golden. Remove from oven and prick with fork again if puffy. Set aside.
Cut peppers into 1 inch (2.5 cm) wide strips and toss with garlic, salt and pepper. Slice mozzarella into thin slices and pat dry.
Start layering peppers, cheese and basil slightly overlapping each other inside edge of puff pastry to fill the space.
Return to oven for about 10 minutes or until cheese melts and pastry is golden. Remove from oven and let stand 5 minutes before slicing and drizzling with balsamic glaze to serve.