To bake mincemeat tarts, mix together flour, sugar, orange peels, butter and egg yolk to make the dough. Form the tart shapes, and fill each with mincemeat, ginger and cinnamon. Bake the tarts in an oven for about 20 minutes, until the crusts are golden.
To make 18 tarts, the dough requires first mixing 1 3/4 cups of flour, 6 tablespoons of powdered sugar, 2 1/2 teaspoons of orange peels and some salt in a processor. Add 1 stick of butter, 1 egg yolk and 2 tablespoons of orange juice. Gather together the completed dough, flatten into a disc and chill for 30 minutes.
Mix together the tart filling with 3/4 cups of mincemeat, 3 tablespoons of crystallized ginger and 1/4 teaspoon of cinnamon. Roll out the dough and use a 2 1/2-inch diameter cookie cutter to cut out 18 dough rounds, and another 2-inch diameter cookie cutter to cut out 18 more. Take muffin cups and fill each with one of the larger dough rounds to form the crust of the tart. Fill the crust in each muffin with 1 teaspoon of the filling, and place a smaller dough round on top to complete the tart.
Finally, preheat an oven to 375 degrees Fahrenheit, and bake the tarts for about 20 minutes until the crusts are golden brown. Allow to cool and serve.