My sister is the chef of the family, and she created this wonderful recipe many years ago. It is a "must" when you visit her house in the mountains of central Mexico. Here she is in the picture, preparing this very recipe. Place meat in a cooking pot, cover with water, add a piece of onion and salt. Bring to a rolling boil. Lower to low heat and simmer until water is almost gone and set aside. Heat oil in a frying pan. Lightly fry meat and place on paper towels to drain the oil. Sauce: Boil tomatoes and peppers with a pinch of salt until soft. Separately, fry garlic and onion. Roast almonds and tortilla in a dry frying pan. Place all these ingredients in a blender, add a little water, and blend until well mixed. Fry this sauce in very hot oil, bring it to a full boil, and lower the heat. Simmer for a few minutes. Season with salt and pepper. Add the meat to the sauce. Add water as necessary, bring back to a boil, and let simmer for a few minutes. Serve hot, garnished with slivered almonds on top. Serves 4.