1. Preheat the oven to 400 degrees F.
2. Heat a grill pan or skillet to medium-high. Cover the bottom with a thin film of oil and add steak. To cook the steak medium-rare, sear it for about 5 minutes per side, or until a thermometer inserted into the center registers 145 degrees F, then let it rest on a cutting board for at least 5 minutes.
3. In a medium saucepot, mix together the beans and corn, a pinch of salt, and 1-2 Tbs. water; heat over medium-low until the mixture is warmed through. Taste for salt and black pepper.
4. When the steak has rested, thinly slice it against the grain into 1- to 2-inch-wide strips. (Against the grain means perpendicular to the grain; this makes it more tender.) Cut the thin strips into 1- to 2-inch pieces.
5. Add the tortilla chips to a medium baking dish. Sprinkle on half the cheeses, then the steak pieces, followed by the bean-corn mixture. Ladle on red-chile sauce to taste; top with the remaining cheeses.
6. Bake until the cheese begins to bubble, about 10 minutes. Remove from the oven to a trivet, and spoon 1/4 cup Green Sauce into the middle of the dish so people can dip into it. Serve with more Green Sauce, for additional dipping.