Cook Beef: In a large skillet, heat 1 tablespoon of vegetable oil over medium heat. Add the ground beef and cook until it's no longer pink, breaking it apart with a spoon.

Add Aromatics: Add the chopped onion and minced garlic to the skillet with the beef. Cook until the onion is translucent.

Season: Stir in the taco seasoning, beef broth, and green chiles (if using). Let the mixture simmer until most of the liquid has evaporated, about 5-7 minutes. Remove from heat and let it cool slightly.

Fill Tortillas: Lay out the flour tortillas on a flat surface. Divide the beef mixture among the tortillas, placing it in the center. Top each with shredded cheese.

Fold: Fold in the sides of each tortilla, then roll them up tightly to enclose the filling.

Secure: Use toothpicks to secure the ends of the tortillas, if necessary.

Heat Oil: In a large skillet or a deep fryer, heat about 1 inch of vegetable oil to 375°F (190°C).

Fry: Fry the chimichangas in batches, seam side down first, turning once, until they are golden brown and crispy, about 2-3 minutes per side.

Drain: Remove the chimichangas from the oil and drain them on paper towels. Remove any toothpicks if you used them.

Serve the chimichangas hot, accompanied by sour cream, guacamole, salsa, and any other desired toppings, such as chopped lettuce and diced tomatoes.