Heat the olive oil in a large skillet set over medium heat. Add the onions and cook, stirring occasionally, until the onions are tender, about 5 minutes.
Add the ground pork, beef broth, red wine, allspice, cinnamon and cloves. Break up the pork with a wooden spoon. Season with salt and pepper. Simmer until the liquid is gone, but the pork is still moist, about 45 minutes.
Pierce the potato in several places with a fork. Microwave until the potato is tender, about 5 minutes. Cut in half, squeeze out the potato into a bowl and discard the potato skin. Mash the potato with the back of a fork until fairly smooth.
Add ¾ cup of the mashed potato to the pork mixture. Stir until completely incorporated and the mixture is sticking together.
Preheat the oven to 350 degrees F. Lightly coat a 9-inch pie dish with cooking spray.
Unroll the defrosted fillo dough and place it under a damp kitchen towel to stop the dough from drying out. Cover whenever the dough is not in use.
Place 1 sheet of the fillo in the pie dish and push down so that the dough fits into the dish. Lightly coat with cooking spray. Turn the pie dish slightly and repeat with another sheet of fillo dough. Continue with 4 more sheets of dough (a total of 6), turning slightly each time so that all sides of the pie dish are covered and lightly coating each layer with cooking spray.
Transfer the meat mixture to the pie dish and spread the meat evenly.
Top the meat mixture with 4 sheets of fillo dough, scrunching each one slightly to fit within the pie dish and lightly coating each layer with cooking spray.
Bake until the fillo dough is golden brown, about 30 minutes.
Let rest for 10 minutes, then carefully cut the pie into 8 pieces. Serve.