Add the flour and butter to a bowl and, using your fingers (or a stand mixer), mix till the mixture resembles breadcrumbs.

Then add in the yolk, sugar, salt and cinnamon and cardamom and mix till a cohesive ball forms. Wrap with plastic wrap and chill for about 30 minutes or so.

Preheat oven to 400 degrees

Add mincemeat and walnuts to a bowl. Grate the apple into the bowl and set aside.

Grab the crust dough from the fridge and roll it out till it's about 1/6th" to 1/4th" of an inch thick. Using a circular pastry cutter, cut out circles to fit a muffin cup. Gently place in muffin cup (can line if needed with parchment paper). Add spoonfuls of mincemeat apple mixture into crusts. Make sure not to add all the way to the top. You can place a smaller circle on top or any sort of decoration of your choice. Bake at 400 degrees for 20 to 25 minutes. Let cool and enjoy. By the way, these pies get better as they age - so you could make these and refrigerate for upto a week before serving.