Line a cast iron skillet with some kind of cooking agent such as shortening or vegetable oil (I used about 1 1/2 tablespoon of bacon grease). Heat over medium high heat and let the oils melt down. Add the diced potatoes and sprinkle with salt and pepper, and any other seasonings you like. Continue to stir and cook occasionally until the potatoes reach your desired consistency. Ours took about 10-12 minutes.
In a large skillet over medium high heat, break the chorizo into small pieces and cook until it darkens and sets a bit, about 5-6 minutes.
In a medium bowl, whisk together the eggs with a dash of pepper and salt. Pour into the chorizo mixture and stir until the eggs set to your desired consistency.
Heat the flour tortillas and layer with a helping of the potatoes, then the chorizo mixture, topped with your desired amount of cilantro, cheese, and salsa. Serve warm.