Cook the ground beef in a skillet over medium heat until fully browned and cooked through, about 7-8 minutes. Drain excess fat.
Warm the flour tortillas slightly to make them pliable.
Place one tortilla flat on a clean surface. Spread about 1/4 cup of nacho cheese sauce in the center.
Layer one tostada shell on top of the cheese sauce.
Add a portion of cooked ground beef evenly over the tostada shell.
Top with a dollop of sour cream, shredded lettuce, diced tomatoes, and shredded cheddar cheese.
Fold the edges of the tortilla carefully toward the center, creating a hexagonal wrap with visible layers at the edges.
Heat a clean skillet over medium heat and carefully place the folded wrap seam-side down.
Pan-fry for 3-4 minutes on each side or until the tortilla is golden brown and crispy.
Remove from skillet and let rest for a minute before serving.