To prepare the sauce, melt butter in a large skillet over medium heat. Add the flour, chili powder, ground cumin, garlic powder, onion powder, oregano, and salt. Stir to combine.
Add the tomato sauce and one cup chicken broth and stir until completely smooth,approximately 3-4 minutes.
Reduce heat to low and gradually add the remaining chicken broth, one-quarter cup at a time, while you work on the filling and assembling the enchiladas. Note: The sauce will continue to thicken as it rests. Adding additional chicken broth, a little at a time, while you work on Steps #4-13 will help maintain the proper consistency.
To prepare the filling, heat the olive oil in a large skillet over medium heat. Add the onions, garlic, and salt, and stir to combine. Cook, stirring frequently, until the onions soften and just start to develop some color, approximately 3-4 minutes
Add the beef to the skillet and break apart with a spatula while it browns. Cook,stirring occasionally, for 6-7 minutes, or until completely browned.
Once beef is browned, carefully drain excess fat from skillet before adding green chilis and three tablespoons of the sauce to season. Stir to combine and reduce heat to low to keep warm.
Placetop oven rack in the center position and pre-heat oven to 350°F. Add three or four spoonfuls of the sauce to a 7”x11”x2” baking dish and use the back of the spoon to lightly cover the bottom of the dish. Set aside.
To assemble the enchiladas, add a small amount of vegetable oil to a small skillet set over medium-high heat. Once the skillet is hot, add one tortilla and toast until nicely browned, approximately 2 minutes. Flip the tortilla and repeat on the other side.
Add a little more vegetable oil to the skillet and with a second tortilla. Place the toasted tortilla on top of the sauce-covered tortilla on the plate, then add one spoonful of sauce on top of it. Use the back of the spoon to spread the sauce until it covers the top surface of the second tortilla. (The excess sauce from the first tortilla will adhere to the bottom of the second tortilla).
Dip the toasted tortilla into the warm enchilada sauce to coat on both sides. Remove as much excess sauce as possible before transferring to a large, rimmed plate. Set aside.
Time-Saving Tip: Add additional oil and the next tortilla to the hot skillet right before you add the sauce to the top of last tortilla on the stack. This will speed up the process of prepping your tortillas significantly vs. waiting to toast the next one until after you have covered the last one in sauce.
Repeat with the remaining tortillas, lightly toasting each tortilla in a little oil on each side, then adding to the stack and evenly coating the top surface with some sauce.
Onceall eight tortillas have been prepped, add a large spoonful of the filling to the top tortilla halfway between the midway point and the bottom edge. Add a little shredded cheese on top and roll the tortilla from the bottom end up.Place the rolled enchilada into the prepared baking dish, seam down.
Repeat this process with the remaining tortillas until all eight enchiladas are in the baking dish, as shown.
If any of the beef filling is left over, spoon it into the baking dish in the space on either end of the enchiladas, as shown. Top with the remaining sauce and shredded cheese and place in the pre-heated oven for 15 minutes, or until the cheese is completely melted and bubbly.
Remove from oven and top with some fresh cilantro right before serving. Add any of the additional toppings you want.