Whisk eggs, milk, salt and pepper together in a small bowl. Set aside. Heat taco meat in a saucepan or in a microwave until hot. Keep warm.
Melt butter in a large non stick skillet. Saute green onion over medium heat until soft. Pour eggs into hot skillet with onion. As mixture sets at the edges, with spatula, gently lift cooked portion to allow uncooked egg to flow underneath. Cook over medium low heat until just firm, about 10 minutes. Spoon warm taco meat and shredded cheese over omelette. Cover skillet until cheese melts.
Place 1 warm tortilla on each of 6 dinner plates. Top each with a healthy slice of taco omelette. Top with tomato, sour cream and salsa, as desired. Roll up tortillas and enjoy.
When you are making tacos, be sure to make extra taco filling so that you can make these the next day. Even without tortillas, this omelette is delicious.