Place the beef chuck roast pieces into the crock pot.
In a small bowl, mix together the beef broth, ground cumin, chili powder, smoked paprika, garlic powder, onion powder, salt, and black pepper.
Pour the spice and broth mixture over the beef in the crock pot.
Add the diced green bell pepper, red bell pepper, and onion to the crock pot, stirring gently to combine.
Cover and cook on low for 6 hours, or until the beef is tender and easily shredded with a fork.
Once cooked, remove the beef from the crock pot and shred it using two forks.
Return the shredded beef to the crock pot and stir to combine with the vegetables and juices.
Heat a large skillet over medium heat and add 1 tablespoon of vegetable oil.
Place one flour tortilla in the skillet, sprinkle 1/4 cup of shredded cheddar cheese evenly over half of the tortilla, then add approximately 1/4 cup of the shredded beef mixture on top of the cheese.
Sprinkle another 1/4 cup of shredded cheddar cheese over the beef, then fold the tortilla in half to cover the filling.
Cook for 2-3 minutes on each side, or until the tortilla is golden brown and the cheese is melted.
Remove the quesadilla from the skillet and keep warm. Repeat the process with the remaining tortillas, beef mixture, cheese, and oil.
Cut each quesadilla into wedges and serve warm with sour cream, salsa, and chopped fresh cilantro.