In frying pan add taco seasoning to ground beef and cook until done.
While the beef is browning slice up tomato, avocado and shred lettuce
Once ground beef is cooked drain any extra fat off.
Turn oven to broil
Generously butter one side of bread
Top unbuttered side of bread with ground beef, then top with shredded cheese.
Place buttered side down in frying pan and cook over medium heat until bread is nicely browned.
If making sandwich with a generous amount of ground beef follow next 2 steps.
Transfer frying pan to oven and broil for a few minutes until cheese is melted. I find if you try to grill the sandwich completely on the stovetop by the time the cheese is melted the bread is burnt. So a few minutes under the broiler works great.
Place second slice of bread under broiler to toast.
Once cheese is melted remove from oven. Top with slices of tomato, avocado and shredded lettuce. Top with 2 slice of toasted bread.