Creating delicious beef quesadillas is straightforward when you follow these easy steps:

1. Heat Olive Oil: In a large skillet, heat the olive oil over medium heat.
2. Cook Onion and Garlic: Add the diced onion and minced garlic. Sauté until the onion becomes translucent, about 3-4 minutes.
3. Brown the Beef: Add the ground beef to the skillet. Cook until browned, breaking it up with a spoon as it cooks.
4. Season the Beef: Stir in the chili powder, cumin, paprika, salt, and pepper. Mix well and cook for another 2-3 minutes until the spices are fragrant.
5. Prepare the Tortillas: Remove the beef mixture from heat. Lay a tortilla flat on a clean surface.
6. Add Filling: On one half of the tortilla, sprinkle a layer of cheese, followed by a portion of the beef mixture. Top with more cheese to help seal the quesadilla.
7. Fold the Tortilla: Carefully fold the tortilla in half, pressing down gently to secure the filling inside.
8. Cook Quesadilla: Wipe the skillet clean and return it to medium heat. Place the folded quesadilla in the skillet. Cook for 3-4 minutes on each side, or until golden brown and the cheese is melted.
9. Repeat: Repeat the process with the remaining tortillas and filling.
10. Slice and Serve: Once cooked, remove the quesadillas from the skillet and let them cool slightly. Slice into wedges and serve with sour cream, salsa, and garnish with fresh cilantro if desired.

Following these steps will yield beautifully crispy beef quesadillas that are packed with flavor.