Place 4 eggs in a saucepan with water and bring to a boil over medium-high heat. Cook for 20 minutes, then let them cool slightly.

Peel the eggs and chop them. Set aside for later.

Preheat the oven to 430°F (220°C).

Unroll one sheet of puff pastry onto its baking paper on a baking sheet.

Poke the pastry all over with a fork to prevent it from puffing up in the oven.

Spread all the tomato sauce evenly over the pastry, leaving a border around the edges so you can seal the empanada later.

Add the well-drained and flaked tuna, spreading it evenly.

Add the chopped hard-boiled eggs and spread them evenly.

Place the second sheet of puff pastry on top and seal the edges with your fingers.

Poke the top of the pastry all over with a fork to prevent it from puffing up.

Beat 1 large egg or 2 small eggs and use a pastry brush to spread it over the top of the empanada so it turns golden when baked.

Bake the empanada at 350°F (180°C) for 35–40 minutes, or until it reaches your desired golden color.

Remove from the oven and let it cool slightly.

Slice and enjoy—it's fabulous!