Preheat the oven to 375°F (190°C) if you plan to bake and serve the burritos immediately. If preparing for the freezer, you can skip this step.
Heat olive oil in a nonstick skillet over medium heat. Add the chopped vegetables and cook for about 4 minutes, stirring often, until softened and fragrant. Transfer to a clean bowl.
Add the sausage to the same skillet. Break it apart with a spatula while cooking until fully browned and no pink remains. Transfer the cooked sausage to the bowl with the vegetables.
Crack the eggs into a mixing bowl, add salt, and whisk well until the mixture is smooth and evenly yellow.
Wipe the skillet clean and melt the butter over medium heat. Pour in the eggs and allow them to sit briefly before gently stirring with a rubber spatula. Cook slowly, folding the eggs until softly scrambled.
Add the cooked eggs to the bowl with the sausage and vegetables. Gently stir the mixture until evenly combined.
Lay each tortilla flat. Add one eighth of the egg mixture slightly off center and sprinkle about 1/4 cup of shredded cheese over the filling.
Fold the sides of the tortilla inward and roll it tightly from the bottom to enclose the filling. Place seam side down.
Place burritos seam side down on a parchment lined baking sheet and bake at 375°F (190°C) for 5 to 10 minutes until lightly golden and warmed through.
Place assembled burritos on a baking sheet and freeze for about 2 hours until solid. Transfer them to a freezer safe bag or container and store for up to 1 month.
Thaw overnight in the refrigerator. Microwave for 30 to 45 seconds to warm the center, then bake at 350°F (175°C) for about 10 minutes until heated through and lightly crisp.