In a large bowl mix together burger, taco seasoning and salsa. Shape mixture into 3 patties. Grill burgers on medium heat on a grill for 6-8 minutes on each side.
Meanwhile, in a small bowl mix sour cream and guacamole. Top burgers with cheese and grill until the cheese has melted.
Remove burgers from the grill. To assemble – put the burger on a bun. Top with green chilies, tomato, French fried onions, and lettuce.
Spread sour cream/guacamole mixture on the bottom of the top part of the bun.