Soak the Ancho and Guajillo chilis in water overnight or for 3 hours at least. The seeds should float to the top and are discarded. Go over Chili each pepper and clean off any dirt and remove stems and pods. Meanwhile, saute the onion in 2 tablespoons of Corn oil till translucent and soft, on a medium heat, stirring often. Turn down the heat and add all the Ancho and Guajillo peppers, and saute to bring out the flavors. Keep stirring on a medium-low heat making sure not to burn anything. After the Chili peppers are sizzling, add in the fresh cilantro and saute for 3 minutes more, then add the Ro-Tel, on a low heat, cover and simmer for 20 minutes, stirring occasionally.
Cook the ground beef till browned and drain off the liquid. Transfer the ground beef to a mixing bowl and with a wooden spoon, mix in 2 tablespoons each of Cumin, oregano, dried onion, cayenne, and white pepper, and set aside. Back to the chili pepper mixture: Let it cool, then put it all in the Blender with 2 cups more Chicken stock and blend till it forms a smooth sauce. Combine the blended peppers with the seasoned Ground Beef & incorporate everything well. This filling mixture should sit and marinate in the refrigerator overnight, or at least 3-4 hours.
Now do the mixing: The first step to mixing the batter is to season the Masa Mix. Open the package and in a large mixing bowl sift together the mix with 3 tablespoons each of the dried onion, cumin, cayenne, oregano, and white pepper. For the actual mixing, start by pouring 3 cups of corn oil into the seasoned Masa Mix, then take an electric mixer on a low speed and as you mix by machine in one hand, use the other hand to slowly pour in a super-small amount chicken stock. You want to keep machine-mixing till it forms a paste. If it doesn't seem to be holding together, add in more oil as you machine-mix. If it's too dry, simply add a larger amount of chicken stock. Once it forms a reasonably batter-like paste, it is ready to be assembled with the filling. Or, it can be folded up and wrapped in plastic, just like a dough, and sit in the refrigerator for up to 2 weeks, for whenever you are ready to assemble and fill the tamales.
Soak the Corn husks in water, overnight, or until 3 hours before Tamales are ready to be assembled. The husks should be just slightly damp when ready to be assembled and filled.
After the filling has sat, marinating in the refrigerator, it needs to be briefly heated to make sure all the flavors have incorporated. This can be done in the microwave, stirring frequently, or on the stove.
Fill a large stock pot that has a steamer insert, with a small amount of water. The water should not touch the bottom of the insert. Set aside.
To start assembling, take a damp corn husk and spread the batter over it. Take a large spoonful of the ground beef filling and put in the middle. Now close up the husk, just like an envelope and wrap in parchment paper, cut to size. Place the filled, parchment-papered tamale, upright, standing up, inside the steamer on top of the steamer insert. Repeat these steps until you use up all the filling and the steamer is lined with tamales standing up. You may place a second layer of filled tamales on top of the first layer, as long as they are standing up. If the stock pot is deep enough, and a large enough amount of tamales to be filled, you might end up having 3 or 4 layers going up the sides of the steamer.
The tamales steam on low for about 3 hours. Check by simply taking one and opening up the parchment to make sure the batter is firm and done. Serve with my Homemade Salsa (see different recipe).