Scrub the tongue thoroughly with water and place in a large pot with enough water to cover the top of the tongue. Add the quartered onion.
Bring just to a boil over medium high heat; lower temperature to medium, and allow the tongue to cook for approximately 3 hours, covered with a lid, until no longer pink (cook approximately 50 minutes per pound of tongue). Check for doneness by piercing the thickest part with a knife. It should enter easily when the tongue has cooked.
Remove the tongue from the pot, and allow to cool until it is just able to be handled without be burning yourself. While the tongue is cooling is a good time to go ahead and peel the tomatoes:
The tongue needs to be skinned while it is still warm. If you allow too much cooling, it will be difficult to peel the skin off. When the cooked tongue is still very warm, but not hot, the skin will almost fall from the meat. Once it is peeled, slice the tongue diagonally against the grain into 1/2-inch slices.
Close the lid and pressure valve to seal. Press the Manual/Pressure Cook button with high pressure setting. Set the cooking time for 25 minutes. After the cooking time is finished allow the pressure to naturally release.
After all the pressure has released and the pin has dropped, press the Keep Warm/Cancel button and open the lid.
Use tongs to remove the tongue from the inner pot and set aside. Allow to cool until it is just able to be handled without be burning yourself. While the tongue is cooling is a good time to go ahead and peel the tomatoes:
The tongue needs to be skinned while it is still warm. If you allow too much cooling, it will be difficult to peel the skin off. When the cooked tongue is still very warm, but not hot, the skin will almost fall from the meat. Once it is peeled, slice the tongue diagonally against the grain into 1/2-inch slices.
In a different pot, or a deep skillet, heat the oil over medium heat. When it is hot, add the onion and saute for a few minutes until translucent. Next, add the garlic and continue to saute approximately for about 30 seconds until aromatic. Add the chopped tomatoes, oregano, thyme, and long green chiles that have been diced. Reduce the heat to medium/medium low and allow the onion/tomato/chili pepper mixture with herbs to simmer approximately 15 minutes (this will cook the tomatoes and increase the amount of liquid in the sauce).
Add the tomato paste and mix well to incorporate into the sauce. Add the chopped capers and stir well. Season to taste with salt and pepper.
Serve with potatoes, Spanish Rice, or some Corn Tortillas or Flour Tortillas to make Burritos.
Makes approximately 5 to 6 servings.
* Learn How To Peel Fresh Tomatoes. Once the skin is off, dice the tomato into small pieces and set aside until ready to use.
** Learn how to roast and peel chile peppers.
Boiled Beef Tongue Recipe - Lengua De Res: https://whatscookingamerica.net/cynthiapineda/lengua/lengua.htm