01 - Preheat your oven to 400°F (200°C). Line a baking tray with parchment paper.
02 - On a lightly floured surface, roll out the thawed puff pastry to form a rectangle approximately 25x30 cm. Carefully transfer the rolled pastry to the prepared baking tray.
03 - Using a sharp knife, lightly score a border about 2 cm from the edge of the pastry, taking care not to cut all the way through. Prick the central area of the pastry with a fork. Brush the scored border with the beaten egg wash.
04 - In a mixing bowl, combine the softened goat cheese, crème fraîche (or sour cream), lemon zest, black pepper, and fine sea salt. Mix until the ingredients form a smooth, homogenous spread.
05 - Evenly spread the goat cheese mixture within the scored border of the puff pastry. Arrange the thinly sliced tomato rounds in overlapping rows over the cheese. Drizzle the tomatoes with extra virgin olive oil and season lightly with salt and pepper.
06 - Place the assembled tart in the preheated oven and bake for 30 to 35 minutes, or until the pastry achieves a golden-brown hue and appears crisp.
07 - While the tart is baking, combine the balsamic vinegar and honey in a small saucepan. Simmer over medium heat, stirring occasionally, until the mixture reduces by approximately half and develops a syrupy consistency. This should take about 5 to 7 minutes. Remove from heat and allow to cool.
08 - Remove the tart from the oven. Scatter the torn basil leaves over the hot tart. Drizzle generously with the cooled balsamic reduction just before serving. Slice the tart and serve it warm or at room temperature.