Place the diced tomatoes in a blender or food processor and blend until smooth then set aside.
Heat the oil in a large sauce pan over medium heat. Gradually add the flour and chili powder while whisking until the mixture is smooth and no lumps are present.
Continue to whisk while you pour in the blended tomatoes and chicken broth. Add the remaining spices and once the mixture begins to bubble slightly turn the heat to low and let simmer for 5 to 10 minutes, whisking occasionally, until the flavors have blended.
Use sauce in a recipe, or store in an air tight container in the fridge for later use. Enjoy!
This recipe makes approximately 3 cups of enchilada sauce and can easily be doubled or tripled.