Preheat oven to 450. Grease a rectangular 11x13 baking dish. And cover 2 large baking sheets with parchment paper
Use a pastry brush to lightly brush oil on both sides of each tortilla. Lay the tortillas out on the two prepared baking sheets. Place in preheated oven and bake until crisp, about 10-12 minutes, flipping half way through. Once crisp remove from the oven and sprinkle with salt.
Layer half of the tortillas in the bottom of the dish. Top with half of the enchilada sauce, followed by half of the cheese, then sprinkle all of the black beans over the cheese. Repeat layers - tortillas, sauce, cheese. Use the back of a spatula to even out the layers and create an even surface for the eggs to sit on.
Change oven temperature to 375.
Carefully crack 6-8 eggs on top of the casserole. Season eggs with salt and pepper.
Bake until egg whites are fully set but yolks are still runny, 20-25 minutes. Watch the eggs closely once you hit the 20 minute mark to avoid overcooking the yolks.
Serve with avocado and salsa.
You can substitute chips for the tortillas and skip the step of crisping the tortillas. Or some stores sell crisp corn tortillas.