Wrap tortillas in plastic wrap or foil.
Combine meatballs with chili powder in a small bowl; mix well.
Pack the meatballs along with guacamole, tomatoes (or peppers), lettuce (or carrot), cheese, sour cream (if using) and lime wedge (if using) in a divided bento-style lunchbox or in separate containers with lids.
Place the wrapped tortillas on top.
Refrigerate or keep cold with an ice pack until ready to serve.
To serve, divide the meatballs, guacamole, tomatoes (or peppers), lettuce (or carrot) and cheese between the tortillas.
Top with sour cream and serve with a lime wedge, if desired.
