In a large skillet, brown beef until no longer pink. Drain if necessary.
Add taco seasoning and water. Bring to a boil.
Reduce heat and simmer until slightly thickened.
Add green chilies and mix well.
Reduce heat to low and allow to cook 5 minutes until flavors develop.
Using a slotted spoon, add meat to bun bottoms.
Top with cheese, allowing it to melt for a few seconds.
Top with lettuce and then tomato or other favorite taco toppings.