01 - Heat olive oil in a large skillet over medium-high heat. Add the finely chopped onion and sauté until translucent, about 2 minutes.
02 - Add the minced garlic and cook for 30 seconds until fragrant. Add the ground beef and cook until thoroughly browned, breaking it apart with a spatula as it cooks, about 5 to 6 minutes.
03 - Stir in the taco seasoning, tomato paste, and water. Reduce heat and simmer for 2 to 3 minutes until the mixture thickens. Season with salt and pepper to taste. Remove from heat and set aside.
04 - Warm the flour tortillas in a microwave for 15 to 20 seconds or in a dry skillet over medium heat until pliable and easy to fold.
05 - Lay each tortilla flat. Spread 2 tablespoons of nacho cheese sauce in the center. Top with a quarter of the seasoned beef mixture, then sprinkle with a generous portion of both cheddar and Monterey Jack cheeses.
06 - Place a tostada shell directly over the cheese layer. Spread 1 tablespoon of sour cream on top of the shell, then layer with shredded lettuce and diced tomatoes.
07 - Working around the tortilla, carefully fold the edges up and over the center filling, pleating as you go, until all edges meet in the middle and the filling is fully enclosed.
08 - Heat a clean large skillet over medium heat. Place the crunch wrap seam-side down and cook for 2 to 3 minutes per side until the exterior is golden brown and crisp.
09 - Slice each crunch wrap in half and serve immediately while hot and crispy.