You definitely need to start the chicken first. I put all the ingredients in my slow cooker (love that thing!) and let sit on the high setting for a few hours. As the chicken cooks, start to shred it and let it simmer in the juices. WARNING: it's going to make your house smell AWESOME!
Ok, when the chicken is at or near done, you can start making your gorditas. In a large bowl, mix the masa harina, water, and 1/4 cup of oil. Wrap the dough in plastic wrap and roll into a thick log. How thick? Well that just depends on how big you want your gorditas to be. Mine were about 3-4 inches in diameter (after flattening, so about 2-3 inch thick log). Divide the log into 1 inch slices. I got about 12 gorditas with this, and this was plenty for 3 people.
Flatten each gordita either with a rolling pin, or you could be more rustic and use your hands like I did. Be careful though, the dough will be VERY fragile so you kind of have to be gentle and loving with it.
Heat a large skillet or griddle under high heat and cook gorditas in batches (I found that 3 at a time fit in the pan nicely) for about 2 minutes per side. Set aside on plate as each one is done. When all gorditas are cooked, either wait until skillet gets cool or get out new skillet if you can't wait. Place enough oil in the skillet to bring it about 1/4 inch up the pan. If you do this with the hot skillet, you'll probably burn yourself, so that's why I said to either get a new skillet or wait until the other one cools. It's all about safety first, right? Right.
When oil is hot enough for frying, add the gorditas, in batches again, and fry for about 2 minutes per side, when they're nice and golden. When each is done, press the center with a spoon to kind of make a little indentation. Dry on paper towel-lined plate.
Top the indentations with the shredded chicken, sour cream, salsa, cheese, and whatever else you'd like to top it with. The toppings are really endless.