#### Prepare the Shredded Beef
**Cook the beef**
In a slow cooker, combine the chuck roast, beef broth, chili powder, cumin, garlic powder, onion powder, smoked paprika, salt, and pepper. Add diced green chilies if using. Cook on low for 8 hours or high for 4–5 hours, until the beef is tender and shreds easily.
**Shred and mix**
Remove the beef from the slow cooker and shred with two forks. Mix the shredded beef with some of the cooking juices to keep it moist and flavorful.
#### Assemble the Chimichangas
**Preheat the oven**
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil.
**Fill the tortillas**
Lay a tortilla flat. Place about 1/3 cup of shredded beef in the center, followed by a generous sprinkle of cheese. Fold the sides of the tortilla inward, then roll it up tightly to seal the filling. Repeat with the remaining tortillas.
**Brush and bake**
Place the chimichangas seam-side down on the prepared baking sheet. Brush each one lightly with vegetable oil or melted butter to help them crisp up. Bake for 20–25 minutes, or until golden brown and crispy.
#### Serve
**Top and enjoy**
Remove from the oven and let cool for 2–3 minutes. Serve with sour cream, guacamole, salsa, and chopped cilantro as desired.