1 Preheat the oven to 350°F.
2 Prepare the sauce. Coat a large skillet with oil and sauté the onions on medium heat until translucent, a few minutes. Add the garlic for a minute more. While the onions are cooking, purée the canned tomatoes in a blender. Add the tomatoes to the onions and garlic. Bring to a low simmer. Start adding the chili powder, one teaspoon at a time, tasting after each addition, until you get to the desired level of heat and chili flavor. For us that's around 2 Tablespoons. But it depends on your taste and how strong the chili powder is that you are using. Note that the tortillas and chicken will absorb some of the heat, so allow for that and let it be a little bit spicier than what you want in the finished dish. Add a teaspoon of sugar if necessary to cut down on the acid from the tomatoes. You want more of the taste of the chili and less of the tomatoes for this sauce. As the sauce simmers, dilute it with water to keep it from getting to thick as it simmers. Remove from heat.
Alternatively, use a prepared canned enchilada sauce, which can be perfectly fine.
3 Mix in 1/4 cup of the sauce with the cooked chicken, and a 1/4 cup of the cheese. Sprinkle with a little salt. Set aside.
4 Prepare the tortillas. There are 2 basic ways to prepare the tortillas - the traditional way of dipping them in the sauce and heating them individually, and my mom's way when she is trying to cut down on the fat.
First the traditional way. Heat a small light skillet on med-high heat. Add a teaspoon of oil (high smoke point oil as indicated above, we use grapeseed oil) to coat the pan. Dip a tortilla in the sauce to coat the tortilla with sauce on both sides. Place the tortilla in the skillet and heat for a few seconds, until the tortilla begin to show some air bubbles. Use a metal spatula to flip to the other side for a few more seconds. Set aside on a plate. Repeat with remaining tortillas. Proceed to the step 5 .
For my mom's low-fat method of heating up the tortillas, she places a small amount of oil in the skillet to coat the pan. Add a tortilla, flip it to its other side. Then add another tortilla on top of the first to soak up some of the excess oil. Flip them both together and add yet another tortilla. Keep adding them wherever there seems to be some excess oil. The idea is to heat the tortillas and soften them with the minimum amount of oil. As the tortillas become soft and heated, remove them to a paper towel to soak up even more excess oil. If you find you need more oil in the pan, add it. With this method, you do NOT get the chili flavor infused in the tortillas. It is a matter of preference. I prefer the first method, excess oil or not, because it has a much richer and spicier flavor. But as my mom says, "Anything goes. This is just a guideline; do what you want."
Note that because we made this batch the low-fat way, the following photos show tortillas not coated in chili sauce, but the method is the same for if you did.
5 Assemble the enchiladas. Use an 8x12 inch pyrex baking dish. Place a couple spoonfuls of the chicken mixture in the center of a tortilla and roll it up. Place in the baking dish and repeat until all dozen of your tortillas are neatly placed in rows in the casserole dish. Cover the tortillas rolls with the remaining sauce.
Sprinkle with the remaining grated cheese. Note that I recall often eating these chicken enchiladas with very little cheese on them. Instead we had probably 2/3 cup of chopped fresh onion that had been soaked in vinegar sprinkled over the top. (My mom, bless her soul, has no recollection of the chicken enchiladas without the sprinkled cheese. But she's in her 70s and sometimes doesn't remember these things. Or she remembers later and doesn't remember that she ever forgot them in the first place. But heck, I'm in my 40s and my memory isn't what it used to be either.)
6 Place in the oven and cook for 10 minutes, or until cheese is bubbly.
Use a metal spatula to serve.
Serve with thinly sliced iceberg lettuce that has been seasoned with vinegar and salt (no oil),guacamoleor avocado slices, and sour cream. Garnish with cilantro.