FOR ENCHILADAS
Preheat the oven to 425°F. Spray a 9×11-inch baking dish with cooking spray.
Place about ⅓ cup of the cheese in the center of a tortilla. Roll and place the seam side down in the baking dish.
Repeat until all the tortillas are filled, arranging them in a baking dish with ⅛ inch in between.
Pour ¼ cup Tex-Mex chili gravy over each enchilada, and sprinkle evenly with grated cheese and onion, if desired.
Bake for 7 to 10 minutes, until the cheese is melted and the sauce is bubbly.
Garnish with a little more cheese. Serve immediately.
FOR TEX-MEX CHILI GRAVY
In a blender, combine the onions, garlic, and ½ cup water. Process on high speed for 1 minute or until smooth.
In a small saucepan over low heat, combine the crumbled beef, 2 cups water, and the processed onion and garlic.
Simmer, uncovered, for 30 minutes.
Using a large spoon, skim the frothy substance that rises to the surface; discard. Repeat 2 or 3 times during the cooking time. Use the spoon to break up clumps of meat for a smooth consistency. Set aside, off the heat.
In a large skillet over medium heat, heat the oil until it shimmers. Lower the heat. Stirring continuously, add the flour and cook until the flour turns a light golden color. Set aside, off the heat.
In a medium saucepan over low heat, heat the broth and 1 cup water until steaming hot, almost boiling. Meanwhile, in a small bowl or container with a lid, combine the chili powder, salt, Holy Trinity, and cayenne pepper, whisking or shaking to blend. Stir the combined spices into the hot broth mixture, blending until smooth
Gradually add the cooked beef and chili powder–broth mixture to the cooked flour, stirring constantly to remove lumps. Stir and cook over low heat for 5 minutes, or until the mixture is almost as thick as ketchup. Set aside, the heat for at least 10 minutes before serving. The sauce may be refrigerated for up to 1 week or frozen for up to 3 months.
FOR TEX-MEX HOLY TRINITY SPICE MIX
Combine the garlic, cumin, peppercorns, and 1 Tbsp water in a molcajete, mortar and pestle, or spice or coffee grinder. Process until the garlic is a smooth paste and the spices are finely ground.
Transfer to a small container with a lid. Store in the refrigerator for up to 1 month.