Measure all of the dry ingredients in small bowl and set aside.
In a medium-sized pot, heat the olive oil over medium heat. Slowly add the flour/spice mixture, whisking constantly for about 1 minute. Whisk in the tomato paste and then slowly add the chicken stock, whisking constantly to remove lumps.
Raise the heat to medium-high to boil, then reduce to maintain simmer. Cook for 5 minutes, whisking often or until the sauce has thickened. Remove from heat and add vinegar and black pepper. Use for enchiladas.
Check your spices and make sure they aren't expired. In order to have great flavor, you want to make sure your spices aren't too old.
Add cold oil to a cold pot and let heat up to proper temperature before adding the spice mixture. You’ll know it is ready when the oil starts to shimmer.
When adding the spice mixture, whisk constantly so nothing burns while also cooking out the flour.
Simmer for at least 5 minutes but the longer you simmer the thicker the sauce will get. You can control how thick you want the sauce by how long you simmer it.
Add vinegar after removing the sauce from heat so it doesn't cook out and helps amp up the flavor of this homemade enchilada sauce.