For the dough:

Sauté the onion, garlic in the sunflower and olive oil combined over low heat until onion is wilted. Strain the oil and reserve it separately. Place the sautéed onions and garlic in a small bowl to use later.

In a large bowl, mix the flour and salt. Dissolve the sugar and yeast in the warm water and let proof for 5 to 10 minutes. Add the water mixture to the flour. Turn the dough onto a floured surface and gradually incorporate ½ cup of the reserved oil, kneading in about 2 tablespoons at time. Save the remaining oil to use in the filling. Continue to knead the dough until you’re tired. Kidding! Knead until the dough is smooth elastic. If you press the dough with your thumb and the imprint bounces back the dough is sufficiently kneaded. If the dough remains indented, more kneading is required. Place the dough in a large oiled bowl, turning to coat. Cover and let sit in a warm spot until doubled. Continue with empanada filling.

For the filling:

In a skillet, sauté the peppers in the reserved oil, covered, until tender. Add the reserved onion and garlic, tuna and tomato puree and cook uncovered until thickened. Salt and pepper to taste.

Divide the dough into two equal pieces. Roll each to 10 x 15 inches. Place one piece on a greased cookie sheet the same size. Spread on the filling, then cover with the other piece of dough, rolling up the edges to seal. Make several slits in the dough and decorate if desired.

Let sit 20 minutes in a warm place. Brush with the egg, and then bake at 375 in the lower third of your oven for 30 minutes or until dark golden brown. Let rest at least 10 minutes (best at room temperature) and then cut into squares.