Preheat the oven to 200°c. Line a large baking tray with parchment paper.
In the bowl of a stand mixer, sift flour into a large bowl and add sugar and cold butter. Mix the ingredients using the paddle attachment. If the dough doesn't come together, add a bit of cold water. Form a ball, wrap the dough in cling film, and refrigerate for about 45 minutes.
Combine peach slices and orange zest in a medium bowl, toss to blend.
Roll the dough into 2 circles (each about 6 inches in diameter) directly on the lined baking tray, dust with additional flour if necessary. Spread soft cheese in the centre, leaving about 2 inches of free edge. Arrange the peach slices on top in concentric circles, overlapping slightly. Use the parchment to help fold the crust border up over the peaches, pinching any cracks in the crust. Brush crust with vegetable oil.
Bake for about 35 minutes, until golden brown. Remove from the oven and let cool for 10 minutes before serving. Garnish with icing sugar and mint leaves.