Ok I'm calling these cheaters enchiladas because I didn't use a traditional recipe. When it comes to authentic Mexican food, I tend to refer to Rick Bayless and his vast knowledge. I cheated by using a store bought rotisserie chicken although after looking at this recipe, I see Bayless did the same thing for the chicken, used store bought rotisserie. So maybe this isn't really cheating after all?
Since I don't have exact measurements due to making two kinds at the same time, I'm going to write this up the way I made it.
1 28oz can enchilada mild sauce (I used Old Elpaso)
1 19oz can enchilada mild sauce
1 10oz can enchilada medium sauce
4 large yellow onions (I prefer vidallia onions but the store didn't have any. However these were about the same size)
3 (2 cup) packages shredded cheese (I typically use the taco blend, but since I didn't realize I'd use all of the cheese up, I only bought two taco blend and one regular mild cheddar)
2 packages medium sized flour tortillas
1 1 pound 13 oz store bought rotisserie chicken (traditional recipe), reserve drippings from bottom of rotisserie package
chili powder and pepper flakes to taste (optional)
Slice the onions and set in a large bowl while you preheat the pan up on medium heat. When pan is heated, coat with olive oil (I didn't measure this) then toss onions in, only as much as your pan can handle. I used a smaller pan so I worked in four batches. Let onions cook a bit and sprinkle with salt and let cook down (the salt brings out their sweetness). If you can multi task without problems then move onto the chicken, and start removing the skin and fat and pulling the meat off the bones, shredding it as you toss into a bowl. Keep an eye on the onions and stir processionally. If you only want the onions to sweat more than caramelize then don't cook them too much. I normally just cook them to remove the bite since they never cook in the oven when I'm making cheese and onion enchiladas. I like raw onions so it's not a huge issue, but it's nice to have cooked onions when eating enchiladas. When onions are desired doneness toss in bowl and repeat with second batch (if you need to cook them in batches).
Keep going with the onions until all are cooked and set aside. Continue shredding chicken when onions are done, give it a quick chop then add drippings from package to shredded chicken and stir together (you'll be surprised how much meat you get from that one bird!). Take about half the cooked onions and mix in with the chicken (add more or less to your preference). If you like your food with a little kick, then mix in some chili powder and pepper flakes in with the chicken mixture. Empty all three cans of enchilada sauce into a large (8 cup) measuring cup and give a quick stir to combine the mild and medium (it was about 6 cups of sauce all together). Pour enough sauce into chicken and onion mixture to be good and wet once it's all stirred together. You'll want to have more sauce in there than you'd think too keep everything from drying out during reheats (if this lasts that long).
Preheat oven to 375F as you wrap and roll. Spray pans (yes I said plural, I used 3, they were more or less 9x13 each, the big casserole one might have been a tad bigger) pam, or better yet, line them all with aluminum foil and then spray the foil to make clean up even easier! I forgot to line them this time and that is the last time I'll forget that. Pour a little enchilada sauce on the bottom of the pans to keep the bottom of the enchiladas moist. Take one package of tortillas and fan them out to separate, set them on a plate or cutting board. Add a good heaping portion of the chicken mixture to one end and sprinkle with cheese (again to your preference, I wound up using an entire 2 cup bag on all of the chicken enchiladas), tightly roll the enchiladas and place seam side down in pan. Repeat until all the chicken enchiladas are done.
Mix one 2 cup package of cheese with the onions and stir in enchilada sauce. Again don't worry about being skimpy with the sauce, as long as you have plenty for the tops of the enchiladas you'll be fine. There's more than enough sauce with the 3 cans to be generous with the fillings. Take the other package of tortillas and fan them out to separate, set them on a plate or cutting board. Just as with the chicken filling, scoop a generous amount of the onion filling onto one end of the tortilla and tightly roll up, placing seam side down in the pan. It's best to keep these separated from the others so that people that don't want/like chicken know which ones these are. It's easiest if you have different kinds of pans to remember which one is which. Repeat with all the onion filling. When the last one is in the pan, evenly pour the sauce over the enchiladas in all three pans. Split the last package of cheese between all three pans, cover with foil and place in oven. Cook for a half hour covered (if not longer), until sauce begins to bubble. Remove foil and rotate the pans around (move the one from the top rack to the bottom and put the two that were on the bottom, on top) and continue to bake until the cheese is cooked.
Let stand a few minutes to cool and serve with sour cream.