Migas are a class Texas brealfast dish. There are hundreds of different versions of the recipe too, with everyone having their favorite way to prepare it. This one is a typical Migas dish, though it adds sour cream and green onion garnish instead of the more typical salsa topping.
In a medium bowl, beat eggs lightly with the milk; set aside.
Melt butter in a large skillet over medium heat; cook and stir onion, garlic, green chiles and tomato in the melted butter until tomato is soft and onion is transparent, about 5 minutes. Pour eggs over the sautéed vegetables, and cook about 2 to 3 minutes, stirring frequently, or until eggs are slightly set.
Sprinkle tortilla chips over eggs, and stir chips into eggs. Turn off heat, and sprinkle both cheeses over the egg mixture. Cover skillet and set aside until cheese is melted and eggs are cooked through, about 5 minutes.
Meanwhile, stack flour tortillas on a microwave-safe plate; microwave until tortillas are warmed, about 30 seconds.
Divide the egg mixture among the warmed tortillas, and top with hot sauce, a dollop of sour cream, or chopped green onions, if desired.