Start by placing a medium-sized saucepan over medium heat. Pour in your neutral oil and let it warm up for about a minute. Once the oil is hot, whisk in the all-purpose flour. This mixture of fat and flour is called a roux, and it is what gives the enchilada sauce its thick, velvety body. Keep whisking constantly for about two minutes.
You are looking for the flour to cook slightly so it loses its raw taste, but you don’t want it to turn dark brown.
Add the chili powder, garlic powder, onion powder, oregano, cumin, and salt directly into the oil and flour mixture. Stir everything together for about thirty seconds to one minute. If the mixture starts to smell scorched, move the pan off the heat immediately.
Add the tomato paste to the spiced roux and stir it in well. The tomato paste adds a hidden layer of umami and a beautiful dark red color to the finished sauce.
Slowly pour in the vegetable broth while whisking vigorously with your other hand. It is best to add the liquid in small splashes at first to prevent lumps from forming in your flour base. Once about half of the broth is in and the mixture is smooth, you can pour in the rest of the liquid.
Bring the sauce up to a gentle simmer over medium-high heat. Once it starts to bubble, turn the heat down to low. Let the sauce cook uncovered for about eight to ten minutes.
Right before you take the pan off the stove, stir in the apple cider vinegar. This tiny amount of acid is a secret trick that brightens all the heavy, earthy spices and makes the sauce taste fresh.
Remove the pan from the heat and let the sauce sit for a few minutes. As it cools down slightly, it will continue to thicken into a perfect consistency for pouring over tortillas.
