Preheat the oven to 400°F (200°C). Wash and dice the bell pepper and onion into small pieces, then add a pinch of salt.

Boil the eggs. In a skillet, sauté the bell pepper and onion until golden.

Drain the oil from the tuna.

Remove the skillet from the heat. Peel the 2 boiled eggs and chop them.

In a bowl, mix the sautéed vegetables with the tuna, chopped eggs, and tomato sauce. Stir well to combine.

On a cool baking sheet, roll out one sheet of dough.

Spread the filling evenly over the dough, leaving about a finger-width border all around.

Beat the egg with a pinch of salt. Once the filling is spread, cover with the second sheet of dough.

Seal all the edges to keep the filling inside. If you have extra dough, use it to decorate the top.

Brush the top of the dough with the beaten egg using a pastry brush.

Cut a small hole in the center of the empanada.

Bake for 20 minutes, or until the empanada is golden brown.

Serve hot or cold (personally, I prefer it cold as it's easier to digest). Plate and enjoy.