In a large skillet over medium-high heat, cook the ground beef, garlic powder, black pepper and onion, crumbling the beef as you cook it, until well browned, 5 to 7 minutes. Transfer with a slotted spoon to a paper towel-lined plate. Pour off any excess grease but do not clean the skillet.
To the same skillet, add the beef broth, tomatoes, tomato paste, chili powder, paprika, cumin, hot sauce and some salt. Smash the tomatoes into small bits as you stir. Bring the mixture to a boil, then reduce to a simmer. Use an immersion blender to puree the sauce. Simmer for 1 hour.
After 1 hour, mix the cornstarch with 1/4 cup water in a small bowl. Add the slurry to the sauce. Raise the heat to medium high and let it boil and thicken for 3 minutes. Return the beef to the pan and stir.
Preheat the oven to 350 degrees F. Soften the tortillas in the microwave, wrapped in a paper towel, for 15 to 45 seconds, depending on your microwave.
Mix together all 3 cheeses in a bowl. Place a couple of tablespoons of cheese in the center of each tortilla, making a line down the center. Roll each tortilla up and place it seam-side down in a 9-by-13-inch pan. Once all the tortillas are in the pan, spoon or ladle the sauce over the top of them. Top with the leftover cheese and bake until bubbly, about 18 minutes.
To make ahead: Assemble the tortillas in the pan and cover with plastic wrap. Put the cooled sauce in an airtight container. Keep the extra cheese for topping in another container. Throw everything into the fridge. When ready to cook, top the tortillas with the sauce and cheese and bake!