How to Make It
Preheat oven to 375°F. Arrange 6 of the tostadas evenly in a large cast-iron skillet, breaking into pieces as needed to cover bottom of skillet. Top evenly with 2⁄3 cup of the enchilada sauce, 1⁄2 cup of the beans, 2⁄3 cup of the Colby Jack cheese, and 1⁄3 cup of the queso blanco. Repeat layers 2 times. Bake until mixture bubbles, 20 to 25 minutes.
During final 5 minutes of baking, heat a large nonstick skillet over medium. Add oil; crack eggs into skillet. Cook until whites are set, 4 minutes.
Arrange cooked eggs on baked tostada mixture. Sprinkle with salt and pepper. Top with avocado, sour cream, cilantro, and jalapeño.