corn tortillas - toasted in a comal or cast iron pan
To Poach the Chicken
Place the in a deep pot and add the salt, along with the two quarts of chicken stock.
Bring to a simmer over medium heat, then cover and reduce heat to low. Simmer for 12 minutes. Remove from heat and set aside for 5-10 minutes so that it can reabsorb some liquid. To ensure it is cooked to the proper temperature, an instant-read thermometer inserted in the thickest part of the breast should read 165 degrees F.
Remove chicken from the liquid and shred thoroughly with two forks.
To Make Tinga de Pollo
Heat a pan over medium-migh heat and add two tbsp. of vegetable oil. Cook the sliced onions for 5 minutes, until they start to soften and become translucent. Add the peeled garlic cloves and cook an additional 3 minutes.
Add the onion, garlic, tomatoes, chipotle peppers, and 1 tbsp. of the adobo from the can. Puree at high speed until completely liquified.
Add 1 tbsp. of vegetable oil to the pan and heat over medium heat. Add contents of the blender, and the oregano, salt, and pepper. Stir, then cook for 10 minutes. A splatter screen will prevent the sauce from making a mess of your stovetop.
Add the shredded chicken and stir very well to coat. Cook an additional 5-10 minutes, until the sauce thickens slightly. Taste for salt and adjust.
Since the tinga de pollo is a wet ingredient, it's best if you use two corn tortillas per taco.