In a mixing bowl, sprinkle sugar, mint, rice flour and liqueur over the berries, mix and let sit for an hour.
Divide mixture in two and spread over half the puff pastry. Wet edges and fold over puff pastry, pinching the edge to seal. Bake at 400F for 15-20 minutes. Let cool.
Whip cream to stiff peaks with sugar. Top turnover with a big dollop of cream.