In a bowl, mix the orange zest, chopped pecans and stem ginger into the mincemeat, then add a splash of brandy. Set aside.
Preheat the oven to 220ºC/425ºF/gas 7. Lay the pastry on a clean work surface with a short edge facing you. Spread thinly and evenly with the mincemeat mixture, leaving a 2.5cm border of pastry along the short edge furthest away from you. Brush the pastry border with a little beaten egg, then, from the edge nearest to you, roll up the pastry tightly like a Swiss roll. Wrap in cling film and pop in the freezer for 10 minutes to firm up.
Unwrap the pastry and cut off and discard the ends to neaten. Slice into 24 rounds, then lightly flatten each one. Using a fish slice, transfer to 2 non-stick baking sheets, spaced apart. Bake in the oven for 15–18 minutes, until cooked through, puffed and golden brown. Place on a wire rack to cool.
When you’re ready to serve, spoon a tiny blob of vanilla ice cream onto each mincemeat palmier. Fill a tray with glasses of good sweet sherry and place a palmier on top of each glass.