Line 2 baking sheets with parchment paper. Preheat oven to 425°F (220°C).

Place a sheet of puff pastry on a baking sheet. Spread the pastry with half of the goat cheese to within a little less than 1/2 inch (1.25cm) on all four sides. Brush the sides with egg & fold them over to form a border. Use a fork to lightly press them down. Repeat with the other sheet of pastry & goat cheese, placing it on the second baking sheet.

Scatter both tarts with the tomatoes & thyme. Sprinkle with salt & pepper. Bake on the lower racks for about 35 minutes, switching baking sheets around halfway through cooking. Cook until pastry is puffed & golden brown & tomatoes are wilted. Cut each tart into 4 to 6 pieces to serve. Serve warm. Serves 8 to 12.