Preheat oven to 400°F (200°C). Roll out your sheet of puff pastry on a floured surface. Cut into 8 pieces (you can either do squares or rectangles) and draw a half inch edge for each tart and pierce the middle with a fork so that air can pass through while it bakes.
Whisk the egg in a bowl and brush the edges of the pastry tarts with the egg wash. Place each tart in a parchment-lined baking sheet and place in the oven for 20 minutes.
While the puff pastry is baking, prepare the ricotta mixture by adding it in a mixing bowl with lemon zest, 1 tablespoon of maple syrup and thyme.
Once puff pastry is ready and golden brown, remove from the oven (but leave the oven on because we'll put back the tarts in shortly) and flatten the inner part of the tart, leaving the border intact.
Add the ricotta mixture and top with the sliced figs, face side up. With a spoon or pastry brush, coat each fig with maple syrup. Place tarts back into the oven for 10 minutes.
Once done, top each tart with a drizzle of maple syrup, a pinch of salt and mint.