Preheat the oven to 375 degrees Fahrenheit, or 190 degrees Celsius. Hold on a second. Prepare a 9×13-inch baking dish by greasing the base.
In the baking dish that you have prepared, lay six tortillas. On top of the tortillas, spread 1/3 of the salsa. On top of the salsa, distribute half of the meat mixture. Top with half of the green onions. Distribute half of the sour cream over the green onions in a random manner. Sprinkle with half a cup each of Cheddar and Monterey Jack cheeses. Layer again. Spread the remaining salsa on top, top with 6 tortillas, and then sprinkle the remaining cheese on top.
Melt the cheeses evenly over the layers and bake for 30 to 45 minutes in a preheated oven until the top is golden brown.
