To make the filling, add the oil and the garlic to a skillet over medium-high heat and sauté for 1 minute. Then add the chopped onion and cook for 3 minutes. Add the tomatoes, bell peppers and the chile and cook for 5 more minutes.
Then add the tuna, the bay leaves, and the olives, stir well and let it cook at low temperature for 5 to 7 more minutes. Season with salt to taste and remove from the heat, let it cool down before preparing the empanadas.
Preheat the oven to 400F. To assemble the empanadas, put a small amount of the tuna stew inside each dough circle and, using your finger, moist the edges of the dough with beaten egg or water to keep them from opening up while baking. Then fold and close it with a fork or pinch and twist with your finger to make them look even nicer.
Lightly brush the outside of the dough with a little bit of the egg wash to create a nicer golden brown color. Bake until golden brown, about 20 minutes. Serve and enjoy!