To make the filling:

Add olive oil, pepper and onion into a pan on medium heat. Cook, stirring occasionally, until onions are translucent and peppers begin to soften for about 3 to 5 minutes. Add garlic and ground meat. When meat is brown, stir in the crushed tomatoes, cumin, coriander, oregano, balsamic vinegar, capers and salt. Reduce heat, cover and and let simmer for 1 hour, stirring occasionally. Set aside to cool.

To prepare the empanadas:

Add egg and a splash of water to a small bowl and lightly whisk then set aside. Line a large baking pan with parchment and set aside. Generously dust a clean surface with flour. Take one ball of dough out of fridge. If using store bought pizza dough, divide it into three to make it easier to work with and use one portion at a time, following these instructions. Using a rolling pin, roll out dough until it is about 1/8 inch thin (less than ½ cm). Using a 3 inch (7.5 cm) round cutter, cut dough into rounds until it is all used up.

Dollop 1 tbsp (15 mL) of the beef mixture onto the centre of each round. Brush edges with some of the egg. Fold the round in half to encase mixture. The dough will be pliable enough for you to stretch and shape as needed. Dust your work surface with flour as needed. Using the tip of a fork press tines into the edge of the empanada to seal the edges together well. Set onto a parchment lined baking pan about 1 inch (2.5 cm) apart. Repeat the process two more times until all the dough is used up.

To Make Ahead:

Freeze empanadas after baking them. Lay flat in a resealable bag and freeze for one hour. Once frozen, you can pile as many as you like into another large resealable bag and they won't stick together. Bake at 350F for 20-25 minutes from frozen.