Lightly flour your work surface and rolling pin, then gently roll out the chilled pie crust into a circle about 1/8 inch thick. Carefully transfer it to your tart pan, pressing it into the edges and trimming any excess dough. Chill the crust for 10 minutes to relax the gluten.
Preheat your oven to 375°F (190°C). Prick the bottom of the crust all over with a fork, then line it with parchment paper and fill with pie weights or dried beans to prevent puffing. Bake for 10 minutes until just set and lightly golden. Remove from oven and let cool slightly.
While the crust bakes, pat the sliced heirloom tomatoes dry with paper towels to remove excess juices. This helps prevent sogginess later. Slice your tomatoes thin and arrange them on a paper towel-lined tray.
Remove the crust from the oven and brush the edges lightly with a beaten egg wash for a glossy finish. Let it cool slightly, then spread crumbled goat cheese evenly over the bottom of the crust.
Layer the sliced tomatoes in concentric circles over the goat cheese, overlapping slightly as you go. Be quick to avoid juices pooling; sprinkle a pinch of salt and pepper over the top and drizzle with olive oil for rich flavor.
Chop fresh basil and sprinkle it generously over the layered tomatoes for a fragrant, bright finish. Drizzle with balsamic glaze to add a sweet tang that complements the acidity of the tomatoes.
Place the assembled tart in the oven and bake for an additional 15-20 minutes, until the crust is golden and crisp, and the tomatoes are slightly bubbling. Keep an eye to prevent edges from burning.
Once baked, remove the tart from the oven and let it cool slightly on a wire rack. The crust should be flaky and crisp, with juicy, colorful tomatoes on top.
Slice the tart into wedges and serve immediately to enjoy the crisp crust, bursting tomatoes, and melty goat cheese. Garnish with extra basil if desired for a fresh aroma.
