For the filling: Place the clean peppers in a medium size saucepan along with 3 cups of water. Turn the heat to medium high. Once the water comes to a boil, turn the heat off and let the peppers soak in that water for 15 minutes. This will allow the peppers to soften. In case they still don’t look soft after the 15 minutes, leave them in for another 5 minutes.
While the peppers are soaking, season the ground beef with salt and pepper and mix well. Heat the vegetable oil in a large skillet at medium-high heat. Once the oil is hot, add the meat and fry it at medium heat. Cook the meat for about 5 minutes, then stir in the chopped onion and minced garlic. Keep cooking for 1 more minute.
Cooking ground beef with dried pepper sauce for Authentic Mexican Tamales.
Add the diced carrots to the skillet and cook for 4 minutes. After that time, stir in the potatoes and keep cooking for about 8 more minutes
At this time, remove the peppers from the soaking water and place them in your blender with ½ cup of the soaking water or clean water. Process the peppers and water until you have a smooth sauce.
Using a strainer, pour the sauce into the skillet. The strainer will catch the leftover bits and pieces from the pepper skins. Stir and check the sauce for seasoning, and add salt if needed. Keep cooking for about 5 more minutes, until the vegetables are cooked. Make sure you do not overcook the vegetables, since they will keep cooking when you steam the tamales. Make sure that the potatoes still have some shape to them, otherwise they will disintegrate when you cook the tamales.