If you're going to use the rotisserie chicken, combine the meat with the onion, garlic, can of green chilies, cumin, salt, and drained corn in a 4 quart (or so) crockpot and cook on high for 3-4 hours, or on low for 6. The onions need to be translucent before going into the tamales. If you don't have time for this step, skip the garlic and onion, and combine the chicken with the chiles, cumin, salt, and drained corn in a mixing bowl. Set aside.
Soften the corn husks by soaking them in very hot water until they are quite pliable.
To make the masa, combine all dough ingredients in a large mixing bowl, and beat on medium-to-high speed until everything is mixed well and the dough is spongy. Check the dough by dropping a little ball of it into a glass of water. It should float. If it doesn't float, this source says to continue to beat the dough.
Take a bit larger than a golf-ball size piece of masa dough, and spread it into a wet corn husk. The dough should be about 1/4 inch thick--you do not want to see the corn husk through the dough. Add a bit of filling, and some cheese. Fold the corn husk over to join the edges of the masa. If you need to add more dough, do so---no filling should peek through. Fold all corn husk edges into the center and place into the bottom of an empty crockpot, seam side down (I used a 6.5 quart, and fit 19 inside).
Repeat. Many, many, many times. It took me about 2 hours to make all of the tamales. If you find that your corn husks are unraveling, you can add another the other way to secure it, and tear off a long piece to tie around. I had to do this a few times. I also needed to add more hot water to the soaking husks to keep them pliable. If you need to step away from the tamale-making-process for a bit, put the lid on your crockpot to keep moisture inside.
When the crockpot is full, put the lid on and cook on high for 4-6 hours, or until a tester tamale looks and tastes done. The tamales on the edges will cook a bit faster. Once your tester looks good (I used the same one, and kept re-wrapping it and adding it back when it wasn't ready), unplug the crockpot and keep the lid off. Don't unwrap any others until they've set for about 15 minutes. My tamales were cooked at 6 hours, but I began checking every 45 minutes at 4 hours.