To make the pastry dough, beat the egg in a large bowl and add in the baking soda, olive oil, wine or cider and salt.
Add in the flour, little by little, and when it gets too difficult to continue mixing with a fork, use your hands. It should be a soft dough (but not sticky). Make it into a ball and cover in plastic wrap for one hour at room temperature.
To make the filling, heat about two tablespoons of olive oil in a heavy frying pan and cook the onions until soft and starting to caramelize. Add in the roasted red peppers and fry for another two minutes or so, and then add the tomato sauce.
Lower the heat to a slow simmer and cook for about 15 minutes, stirring often.
Add in the tuna, chopped olives, chopped eggs, Worcestershire sauce (or anchovy paste), honey and paprika. Taste and adjust the salt.
Preheat the over to 350°F (175°C) and divide the dough in half, with one half slightly bigger than the other. Grease an 11 inch pan with oil and roll out the larger half of the dough so that will completely cover the bottom of the pan and the edges.
Using your rolling pin, transfer the dough to the pan and gently mold it to fit the pan without stretching the dough. Trim the edges if necessary.
Beat the egg white and brush over the the dough.
Bake the base for 10 minutes and then remove and let cool.
Once cool enough (10 to 15 minutes) cover with the tuna filling.
Roll the other half of the dough large enough the cover the top of the empanada and make sure the edges meet.
Brush the empanada with the beaten egg yolk mixed with one teaspoon of water.
Bake in the oven for 40 minutes and serve hot or cold.