01 - Combine diced tomatoes, red onion, jalapeño, cilantro, lime juice, and salt in a bowl. Mix well and set aside.
02 - Mash avocados in a separate bowl. Stir in tomato, red onion, cilantro, lime juice, salt, and pepper. Cover and refrigerate until serving.
03 - Heat 1 tbsp vegetable oil in a skillet over medium heat. Sauté onion and garlic for 2 minutes. Add ground beef and cook, breaking up with a spoon, until browned, about 5-6 minutes. Drain fat if needed.
04 - Stir in diced bell pepper, cumin, smoked paprika, chili powder, salt, and black pepper. Cook for an additional 3-4 minutes, then remove from heat.
05 - Lay tortillas flat. Sprinkle cheese over half of each tortilla, add beef mixture, then top with more cheese. Fold tortillas in half to enclose filling.
06 - Heat remaining vegetable oil in a large skillet over medium heat. Cook quesadillas in batches for 2-3 minutes per side until golden and cheese is melted. Transfer to a cutting board and slice into wedges.
07 - Serve quesadillas warm, accompanied by salsa and guacamole.