Heat a large skillet over medium-high heat. Add oil and add chorizo to the pan. Break up with a spatula or spoon. Cook for 5 to 6 minutes, or until cooked through. Transfer to a paper-towel lined plate.
Add more oil if needed. Add potatoes to the pan, and cover the pan. Add a few Tablespoons of water and let it cook down if needed. Season with salt and pepper.
In a small bowl, whisk eggs, salt, and pepper. Reduce the heat to medium low, and add the chorizo back into the pan. Pour eggs into the pan, and cook until set, about 2 minutes.
While the eggs are cooking, heat the tortillas. I like to use my griddle pan for this. When you have cooked one side, flip the tortilla and add a generous amount of cheese. Let it melt for a few seconds.
Top the tortillas with the egg mixture. Add cilantro, sour cream, and salsa. If you like, add a squeeze of lime.
To make the salsa: Put everything in the food processor. Pulse for 7 to 8 times. I like a smoothish salsa, so I let it go a little longer. Check for seasoning add salt as needed.