Preheat oven to 300 degrees. Save time and cook chorizo (if raw) and egg mixture at the same time. If you have cooked chorizo, dice and add to egg mixture.
Cook chorizo in a small saucepan over medium heat until light and crispy. Set aside and divide into 4 portions in the pan. Beat eggs with salt, pepper, and cumin. Heat olive oil in a large saucepan over medium-low heat. Add onion and garlic and cook for 2 min. Add eggs and cilantro and scramble until soft. Set aside and divide into 4 portions in the pan. Also divide the avocado, cilantro, tomatoes, and cheese.
Mix the sour cream and ranch together, set aside. Spoon 1 portion of the egg mixture and chorizo into the center of a tortilla. Top with avocado, cheese, tomatoes, a light squeeze of lime, a spoonful of the sour cream dressing, and the salsa/sriracha if desired. Roll up the burrito, and place seam side down on a baking sheet. Make the remaining 3 burritos. Place in the oven for 10 min., then serve warm.