Filling: In a pot, add chicken breast and 2 quarts of water. Boil until chicken is cooked. Remove it and cool on a plate, then shred it. Strain the broth, and reserve 3 cups for later use.
Clean the pot and saute the onion, green peppers, garlic, parsley, and chili if using for about 3 to 4 minutes. Add shredded chicken, chicken broth (3 cups), peas, raisins, potatoes, sugar, salt, pepper, cumin, oregano, and bay leaf. Once it starts to boil, lower the heat and simmer for 5 minutes.
While that is simmering, in a small bowl add the gelatin with 3 tablespoons of water at room temperature, mix and let it sit for a couple of minutes.
After 5 minutes of simmering, taste and see if you need more salt or more chili; remove the bay leaf and add the gelatin. Mix well and cook for 1 more minute and turn off the heat.
Let it cool a bit in the pot and then move to an airtight container. Add the eggs, mix and chill for at least 4 hours, or overnight.
Dough: In a large bowl, mix flour, sugar, salt, urucú (if using), egg yolk, and lard. Add the water at room temperature, mix until everything comes together.
On a flat, floured surface, knead for 10 minutes, or until smooth. (If you have a kitchen aid, you can use it to knead).
Let the dough rest for 20 minutes. Cover it with a damp cloth.
After resting, divide the dough into 20 equal portions (I weighed each ball at 50 grams - about 1.7 ounces).
Working with one portion of dough at a time, form an even ball with circle movements between the palm of the hand and a flat surface.
Place the dough on a plate, or on parchment paper (the color can dye the container), and cover with a damp cloth for 20 minutes.
Working with one portion at a time, roll each ball out onto a flat, floured surface. They should be about 12 centimeters in diameter (4.7 inches), and ¼ centimeter thick (about 1/8 inches).
Place the empanada discs in an airtight bag or container (remember that the color will dye the container, but you can cover it with parchment paper so that this does not happen) and store in the refrigerator for 2 to 3 hours.
How to fill: Take out only 5 empanada discs at a time, and a little filling. Try to keep the rest in the fridge.
If the empanada disc has a lot of flour on the edges, wet your fingertips and run a little water around it.
Place an empanada disc in one hand or a plate, add 1 tablespoon and a half of the filling, and an olive. Bring the edges of the middle together and press with your fingers. Keep pressing the edges, but leave a 1-centimeter (1/4 inch) gap at one end.
With both hands, press the salteña (like hugging it) so that the air comes out. Press tip that was still open, to close.
With your index finger and thumb, press the entire edge again.
To seal, press with your thumb and index finger, fold the corner over the edge into a triangle, and press again. Continue until the entire salteña is sealed. Bring the tip and fold it underneath the salteña.
Place salteñas on a greased baking tray with the seal or repulgue facing upwards. Leave a space of 5 centimeters (2 inches) between each salteña.
Brush each salteña with a mixture of 1 egg white + 2 tablespoons of water.
Heat the oven to 245C (470F) degrees. In a gas oven, it sometimes takes 20 to 40 minutes.
Bake the salteñas for 20 minutes and serve hot with a strawberry, banana, or peach batido (milk, fruit, and sugar).