Place the 2 lb pechugas de pollo sin hueso, sin piel in a large Saucepan in a single layer. Add the 4 cups agua fría suficiente para sumergir completamente el pollo, 2 cups caldo de pollo, smashed 2 cloves dientes de ajo aplastados, 1 whole hoja de laurel, 5 whole granos de pimienta negra, 1 tsp sal kosher, and 2 stalks tallos de apio cortados en trozos grandes, para el caldo de escalfado pieces (if using). The liquid should fully cover the 2 lb pechugas de pollo sin hueso, sin piel — add more 4 cups agua fría suficiente para sumergir completamente el pollo if needed.

Bring the Pot to a gentle simmer over medium heat. This should take about 10–12 minutes. Do not let it reach a rolling boil — a gentle simmer with small bubbles is the goal for tender 2 lb pechugas de pollo sin hueso, sin piel.

Once simmering, reduce the heat to medium-low and cook for 8–10 minutes, or until the thickest part of the 2 lb pechugas de pollo sin hueso, sin piel registers 165°F on an instant-read Meat Thermometer. Larger breasts may take a minute or two longer.

Remove the Pot from the heat. Transfer the 2 lb pechugas de pollo sin hueso, sin piel to a Cutting Board and let it rest for 5 minutes. Then let it cool completely — about 20–25 minutes at room temperature, or speed it up by placing it in the refrigerator.

Once fully cooled, chop the 2 lb pechugas de pollo sin hueso, sin piel into roughly 3/4-inch cubes, or shred it with two forks for a chunkier, more rustic texture. Transfer to a large Mixing Bowl.

In a small Mixing Bowl, whisk together the ½ cup mayonesa, 2 tbsp mostaza Dijon, 1 tbsp jugo de limón fresco, 1 tsp vinagre de sidra de manzana, 1 tsp sal kosher, 5 whole granos de pimienta negra, and 2 cloves dientes de ajo aplastados until completely smooth. Taste and adjust seasoning as needed.

Add the diced 2 stalks tallos de apio cortados en trozos grandes, para el caldo de escalfado, 0.25 whole cebolla roja picada finamente, and fresh 2 tbsp perejil fresco picado finamente (and 1 tbsp eneldo fresco picado finamente, if using) to the Mixing Bowl with the 2 lb pechugas de pollo sin hueso, sin piel. If using ½ cup uvas rojas sin semillas partidas por la mitad and ¼ cup nueces tostadas / ¼ cup nueces tostadas, add them now as well.

Pour the dressing over the 2 lb pechugas de pollo sin hueso, sin piel and vegetables. Fold everything together gently with a Spatula or large Wooden Spoon until evenly coated. Avoid over-mixing to keep the 2 lb pechugas de pollo sin hueso, sin piel pieces intact.

Taste and adjust seasoning with additional 1 tsp sal kosher, 5 whole granos de pimienta negra, or 1 tbsp jugo de limón fresco. Cover and refrigerate for at least 30 minutes before serving to allow the flavors to meld. Serve chilled.