In a medium pot, whisk together vegetable oil and flour for the gravy over medium heat. Keep whisking until the mixture turns a light, tan color, about 5 minutes.
Whisk in all the spices and cook for another 30 seconds. Then start whisking in beef stock in a thin stream. Once stock is whisked in, bring gravy to a slight simmer and cook until it thickens nicely, about 2-3 minutes, whisking occasionally.
To make enchiladas, Slice peppers and grate cheese. Add peppers to a large skillet with a drizzle of olive oil over medium high heat. Add diced onions (reserve a few tablespoons for top of enchiladas) and a pinch of salt. Cook until veggies are just soft, about 2-3 minutes. Remove from heat.
Add 1/4 cup oil to a large skillet over medium heat. Working with one tortilla at a time, let it heat in the oil for 5-10 seconds per side. Then remove tortilla and let drain on a paper towel. Repeat with all the tortillas.
Once all tortillas are warmed and flexible, work with one at a time. Fill it with some of the peppers and onions and a small handful of cheese. Roll it tightly.
Lightly oil an 9×13 baking dish and pour in 1/2 cup of the chili gravy. Then add rolled enchiladas to the baking dish. Fit as many as you can. You should be able to fit 12 at a minimum.
Pour most of the chili gravy over the top of the enchiladas once they are all in the pan. It’s okay to reserve some gravy to serve on the side later. Cover enchiladas with leftover cheese and onions.
Bake for 15 minutes and then let cool briefly before serving.