Make the chili
Position an oven rack about 4 inches from the broiler and heat the broiler on high. Broil the chiles on a large, heavy-duty rimmed baking sheet, turning with tongs as needed, until charred on all sides, about 10 minutes total. Transfer the chiles to a large bowl, cover with plastic wrap, and set aside until cool enough to handle. With gloved hands, peel, seed, and finely chop the chiles; set aside.
Put the ground beef in a large bowl. Mix in 3 Tbs. of the spice mixture.
Line a plate with paper towels. Heat the oil in a 5- to 6-quart heavy-duty pot over high heat. Add the beef and cook, stirring often, until browned, 4 to 5 minutes. Use a slotted spoon to transfer the beef to a medium bowl and set aside.
Put the tortillas in the hot oil and fry on both sides, turning occasionally with tongs, until golden-brown and crisp, 3 to 5 minutes. Transfer the tortillas to the paper-towel-lined plate and set aside.
Reduce the heat to medium. Add 1-1/2 cups of the onions and the remaining spice mixture to the pot. Cook for 15 seconds, stirring and scraping the bottom of the pan constantly. Add 1/2 cup of the roasted chiles, half of the bell peppers, and half the jalapeños. Cook the mixture, stirring frequently, until the green peppers are softened, about 8 minutes. Stir in the garlic and cook, stirring, for 30 seconds.
Stir the flour into the vegetables and cook for 2 minutes, stirring constantly and scraping any browned bits from the bottom of the pan. Add 1 cup of the broth, stirring and scraping the bottom of the pan until no lumps remain. Add the remaining 4 cups of broth and 1 Tbs. salt, stir, and return to a boil.
While the mixture comes to a boil, transfer 1 cup of the broth mixture to a food processor. Crumble in the fried tortillas and process until the tortillas are finely chopped. Pour the tortilla-broth mixture back into the pot and stir in the remaining onions, bell peppers, and the meat.
Return the mixture to a boil, reduce the heat to medium low to low and simmer, stirring occasionally and skimming the surface as needed, until the chili is thick, about 50 minutes.
Stir in the remaining roasted chiles and jalapeños and simmer, stirring occasionally, for 15 minutes. Skim off any oil that rises to the surface. Season to taste with salt and serve.
You can make the chili up to 4 days ahead; keep in an airtight container in the refrigerator and gently reheat to serve.
Garnish this chili with crunchy fried corn tortilla strips, if you like, and serve with more warm tortillas on the side.