Step 1: Brown the ground beef in a large skillet over medium-high heat. Break it up with a spoon as it cooks. Once no pink remains, drain any excess fat.
Step 2: Add the taco seasoning and water to the browned beef. Stir well and simmer for 5-7 minutes, or until most of the liquid has evaporated and the beef is well-coated. Set aside.
Step 3: Lay out one large flour tortilla on a clean, flat surface. If stiff, microwave for 10-15 seconds to make it more pliable.
Step 4: Spread about 1/4 of the nacho cheese sauce evenly in the center of the large tortilla, leaving about a 1-inch border around the edge.
Step 5: Spoon about 1/4 of the seasoned ground beef mixture over the nacho cheese sauce.
Step 6: Place a crispy tostada shell directly on top of the beef.
Step 7: Spread about 1/4 of the sour cream over the tostada shell.
Step 8: Top the sour cream with 1/4 of the shredded lettuce, diced tomatoes, and shredded cheddar cheese.
Step 9: Place a small flour tortilla directly on top of the fresh toppings.
Step 10: Carefully begin folding the edges of the large tortilla over the small tortilla, working your way around in a circular motion. Overlap the folds to completely enclose the filling. Press down gently to secure the wrap.
Step 11: Heat a large, dry skillet or griddle over medium heat. Place the folded crunchwrap seam-side down in the hot skillet. Cook for 3-4 minutes, or until golden brown and crispy.
Step 12: Carefully flip the crunchwrap and cook for another 3-4 minutes on the other side, until golden and the filling is heated through and the cheese is melted. Repeat for the remaining crunch wraps.
Step 13: Remove from the skillet, let cool for a minute, then slice in half and serve immediately.