Dough (if homemade): Pulse flour, butter, and salt in a food processor until crumbly. Add chia seeds, egg, and ice water; pulse until a ball forms. Chill 30 min. Roll to 3 mm (⅛ inch) and line a 9-inch (23 cm) tart pan. Or: Use store-bought puff pastry.
Assemble: Preheat oven to 200°C (395°F). Sprinkle Gruyère over rolled-out dough. Layer pear slices evenly. Dollop Gorgonzola in several places. Scatter walnuts and torn basil on top.
Bake: 15-20 min until golden. Drizzle with honey.
Serve: Slice and serve warm or at room temperature.
