Preheat oven to 375 degrees F. Lightly coat a 3-quart rectangular baking dish with cooking spray. Arrange potato nuggets in dish.
In a large mixing bowl combine eggs, milk, oregano, cumin, chili powder, and garlic powder. Beat with a rotary beater or wire whisk until combined. Pour egg mixture over potato nuggets.
Bake for 35 to 40 minutes or until a knife inserted near center comes out clean. Sprinkle cheese evenly over egg mixture. Bake about 3 minutes more or until cheese melts. Let stand for 10 minutes before serving. Top with salsa and cilantro and serve with sour cream.