Begin by dicing the onion, bell peppers, and jalapeño if you're using it. Crumble the breakfast sausage or chorizo into small pieces to ensure even cooking. Slice the avocado for topping later. This prep should take about 10 minutes, and having everything ready will make assembling the Spicy Southwest Breakfast Burritos a breeze.

In a medium bowl, crack open the large eggs and add 1/4 cup of milk along with salt and black pepper. Whisk the mixture vigorously until well combined and slightly frothy, which will help create fluffy eggs. This step should take around 2 minutes. Set the bowl aside as you prepare to sauté the vegetables.

Heat 1 tablespoon of olive oil in a large nonstick skillet over medium heat for about 2 minutes until hot. Add the diced onion and bell peppers, along with jalapeño if desired. Sauté the mixture for about 5 minutes until the vegetables are softened and fragrant, forming the flavorful base for your burritos.

Pour the whisked egg mixture into the skillet with the sautéed vegetables, stirring gently with a spatula. Cook for about 3 to 4 minutes, allowing the eggs to set but still remain slightly runny. This will ensure your Spicy Southwest Breakfast Burritos have a creamy texture once combined with all ingredients.

Just before the eggs are completely set, stir in the crumbled sausage and let it mingle with the mixture. Sprinkle 1/2 cup of shredded cheddar cheese over the top and remove the skillet from heat once the cheese has melted, about 1-2 minutes. This fusion creates a hearty and flavorful filling for your burritos.

Lightly warm the large flour tortillas in a skillet or microwave for about 30 seconds until pliable. This step is crucial for easy rolling when assembling the Spicy Southwest Breakfast Burritos, allowing the tortillas to embrace the delicious filling comfortably.

Spoon a generous portion of the egg and sausage mixture into the center of each warmed tortilla. Top with salsa, a slice of avocado, and a sprinkle of fresh cilantro. Carefully wrap the tortilla around the filling, folding in the sides, and ensure it’s tightly enclosed. This step will take a few minutes, but it’s well worth it for a satisfying bite.

Serve your Spicy Southwest Breakfast Burritos immediately while they're warm, inviting, and ready to enjoy! Consider adding a dollop of sour cream and extra salsa on the side for extra flavor. They’re perfect for a hearty breakfast that will kickstart your day with energy!